diff --git a/string/1-pangrams.c b/string/1-pangrams.c
new file mode 100644
index 0000000..cc536e0
--- /dev/null
+++ b/string/1-pangrams.c
@@ -0,0 +1,31 @@
+#include <stdio.h>
+#include <string.h>
+
+int main(int argc, char const *argv[])
+{
+    char small[26] = {0};
+    char big[26] = {0};
+    int i, n;
+    char s[1000];
+    while (scanf("%s", &s[strlen(s)]) == 1);
+    n = strlen(s);
+    for (int i = 0; i < n; i++) {
+        if (s[i] >= 'a' && s[i] <= 'z') {
+            small[s[i] - 'a'] = 1;
+        }
+        else if (s[i] >= 'A' && s[i] <= 'Z') {
+            big[s[i] - 'A'] = 1;
+        }
+    }
+
+    for (int i = 0; i < 26; i++) {
+        if (!(big[i] == 1 || small[i] == 1)) {
+            printf("not pangram");
+            return 0;
+        }
+    }
+
+    printf("pangram");
+
+    return 0;
+}
diff --git a/string/1-pangrams.php b/string/1-pangrams.php
new file mode 100644
index 0000000..744c4b5
--- /dev/null
+++ b/string/1-pangrams.php
@@ -0,0 +1,17 @@
+<?php
+
+$handle = fopen("php://stdin", "r");
+$string = fgets($handle);
+
+$string = strtolower($string);
+
+$exists = true;
+
+foreach (range('a', 'z') as $c) {
+    if (strpos($string, $c) === false) {
+        $exists = false;
+        break;
+    }
+}
+
+echo ($exists ? "pangram" : "not pangram") . PHP_EOL;
diff --git a/string/10-palindrome-index.php b/string/10-palindrome-index.php
new file mode 100644
index 0000000..eb1cdaf
--- /dev/null
+++ b/string/10-palindrome-index.php
@@ -0,0 +1,42 @@
+<?php
+
+$handle = fopen("php://stdin", "r");
+fscanf($handle, "%d", $T);
+
+while ($T --) {
+    fscanf($handle, "%s", $str);
+
+    $start = 0;
+    $end = strlen($str) - 1;
+
+    while ($start < $end) {
+        if ($str[$start] == $str[$end]) {
+            $start ++;
+            $end --;
+        } else {
+            break;
+        }
+    }
+
+    if ($start >= $end) {
+        echo "-1\n";
+        continue;
+    }
+
+    $left = true;
+    $start_temp = $start;
+    $end_temp = $end;
+    $start_temp ++;
+    while ($start_temp < $end_temp) {
+        if ($str[$start_temp] == $str[$end_temp]) {
+            $start_temp ++;
+            $end_temp --;
+        } else {
+            $left = false;
+            break;
+        }
+    }
+
+    echo $left ? $start : $end;
+    echo "\n";
+}
diff --git a/string/11-reverse-shuffle-merge.php b/string/11-reverse-shuffle-merge.php
new file mode 100644
index 0000000..9007e9a
--- /dev/null
+++ b/string/11-reverse-shuffle-merge.php
@@ -0,0 +1,5 @@
+<?php
+
+$handle = fopen("php://stdin", "r");
+fscanf($handle, "%s", $S);
+
diff --git a/string/12-the-love-letter-mystery.cpp b/string/12-the-love-letter-mystery.cpp
new file mode 100644
index 0000000..723c5bb
--- /dev/null
+++ b/string/12-the-love-letter-mystery.cpp
@@ -0,0 +1,21 @@
+#include<bits/stdc++.h>
+
+using namespace std;
+
+int main()
+{
+    int t,i;
+    cin>>t;
+    while(t--)
+    {
+        string str;
+        cin>>str;
+        int s = 0;
+        for(i=0 ; i< str.length()/2 ; i++)
+        {
+              s += abs(str[i] - str[str.length()-i-1]);
+        }
+        cout<<s<<endl;
+    }
+    return 0;
+}
diff --git a/string/12-the-love-letter-mystery.php b/string/12-the-love-letter-mystery.php
new file mode 100644
index 0000000..c603ab6
--- /dev/null
+++ b/string/12-the-love-letter-mystery.php
@@ -0,0 +1,26 @@
+<?php
+
+$handle = fopen("php://stdin", "r");
+fscanf($handle, "%d", $T);
+
+while ($T --) {
+    fscanf($handle, "%s", $S);
+
+    $length = strlen($S);
+    $start = 0;
+    $end = $length - 1;
+    $count = 0;
+    while ($start < $end) {
+        if ($S[$start] == $S[$end]) {
+            $start ++;
+            $end --;
+            continue;
+        } else {
+            $count += abs(ord($S[$start]) - ord($S{$end}));
+            $start ++;
+            $end --;
+        }
+    }
+
+    echo $count . PHP_EOL;
+}
diff --git a/string/13-common-child b/string/13-common-child
new file mode 100755
index 0000000..1f2b901
Binary files /dev/null and b/string/13-common-child differ
diff --git a/string/13-common-child.cpp b/string/13-common-child.cpp
new file mode 100644
index 0000000..fdcc626
--- /dev/null
+++ b/string/13-common-child.cpp
@@ -0,0 +1,36 @@
+#include <iostream>
+#include <algorithm>
+#include <string>
+
+using namespace std;
+
+int main(int argc, char const *argv[])
+{
+    string s1, s2;
+    cin >> s1 >> s2;
+    int length = s1.length();
+    int **array = new int*[length + 1];
+    for (int i = 0; i < length + 1; ++i)
+    {
+        array[i] = new int[length + 1];
+    }
+
+    for (int i = 0; i < length; ++i)
+    {
+        for (int j = 0; j < length; ++j)
+        {
+            if (s1[i] == s2[j])
+            {
+                array[i + 1][j + 1] = array[i][j] + 1;
+            }
+            else
+            {
+                array[i + 1][j + 1] = max(array[i + 1][j], array[i][j + 1]);
+            }
+        }
+    }
+
+    cout << array[length][length] << endl;
+
+    return 0;
+}
diff --git a/string/2-funny-string.cpp b/string/2-funny-string.cpp
new file mode 100644
index 0000000..006025d
--- /dev/null
+++ b/string/2-funny-string.cpp
@@ -0,0 +1,35 @@
+#include <iostream>
+#include <string>
+#include <cmath>
+
+using namespace std;
+
+int main(int argc, char const *argv[])
+{
+    string s, r;
+    int times;
+    cin >> times;
+
+    for (int i = 0; i < times; ++i)
+    {
+        cin >> s;
+        int len = s.length();
+
+        bool funny = true;
+        for (int j = 1; j < len; ++j)
+        {
+            if (abs(s[len - j] - s[len - j - 1]) != abs(s[j] - s[j - 1])) {
+                funny = false;
+                break;
+            }
+        }
+
+        if (funny) {
+            cout << "Funny" << endl;
+        } else {
+            cout << "Not Funny" << endl;
+        }
+    }
+
+    return 0;
+}
diff --git a/string/2-funny-string.php b/string/2-funny-string.php
new file mode 100644
index 0000000..06ad857
--- /dev/null
+++ b/string/2-funny-string.php
@@ -0,0 +1,20 @@
+<?php
+
+$handle = fopen("php://stdin", "r");
+fscanf($handle, "%d", $T);
+
+for ($i=0; $i < $T; $i++) {
+    $s = fgets($handle);
+    $s = trim($s);
+    $r = strrev($s);
+
+    $funny = true;
+    for ($j=1; $j < strlen($s); $j++) {
+        if (abs(ord($s[$j]) - ord($s[$j - 1])) != abs(ord($r[$j]) - ord($r[$j - 1]))) {
+            $funny = false;
+            break;
+        }
+    }
+
+    echo $funny ? "Funny\n" : "Not Funny\n";
+}
diff --git a/string/3-alternating-characters.cpp b/string/3-alternating-characters.cpp
new file mode 100644
index 0000000..4c654e9
--- /dev/null
+++ b/string/3-alternating-characters.cpp
@@ -0,0 +1,27 @@
+#include <iostream>
+#include <vector>
+#include <algorithm>
+
+using namespace std;
+
+int main(int argc, char const *argv[])
+{
+    int T;
+    cin >> T;
+
+    while (T --) {
+        string str;
+        cin >> str;
+
+        int ans = 0;
+        for (int i = 0; i < str.length() - 1; ++i)
+        {
+            if (str[i] == str[i + 1])
+                ans ++;
+        }
+
+        cout << ans << endl;
+    }
+
+    return 0;
+}
diff --git a/string/3-alternating-characters.php b/string/3-alternating-characters.php
new file mode 100644
index 0000000..cb50966
--- /dev/null
+++ b/string/3-alternating-characters.php
@@ -0,0 +1,17 @@
+<?php
+
+$handle = fopen("php://stdin", "r");
+fscanf($handle, "%d", $T);
+
+for ($i=0; $i < $T; $i++) {
+    fscanf($handle, "%s", $str);
+
+    $count = 0;
+    for ($j=1; $j < strlen($str); $j++) {
+        if ($str[$j] == $str[$j - 1]) {
+            $count ++;
+        }
+    }
+
+    echo $count . PHP_EOL;
+}
diff --git a/string/4-game-of-thrones.cpp b/string/4-game-of-thrones.cpp
new file mode 100644
index 0000000..f6e8b65
--- /dev/null
+++ b/string/4-game-of-thrones.cpp
@@ -0,0 +1,37 @@
+#include <iostream>
+#include <vector>
+#include <algorithm>
+
+using namespace std;
+
+int main(int argc, char const *argv[])
+{
+    string str;
+    cin >> str;
+    int A[26];
+    for (int i = 0; i < 26; ++i)
+    {
+        A[i] = 0;
+    }
+    for (int i = 0; i < str.length(); ++i)
+    {
+        A[str[i] - 'a'] ++;
+    }
+
+    int sum = 0;
+    for (int i = 0; i < 26; ++i)
+    {
+        sum = sum + (A[i] % 2);
+    }
+
+    if (sum >= 2)
+    {
+        cout << "NO" << endl;
+    }
+    else
+    {
+        cout << "YES" << endl;
+    }
+
+    return 0;
+}
diff --git a/string/4-game-of-thrones.php b/string/4-game-of-thrones.php
new file mode 100644
index 0000000..8ab595b
--- /dev/null
+++ b/string/4-game-of-thrones.php
@@ -0,0 +1,43 @@
+<?php
+
+$handle = fopen("php://stdin", "r");
+fscanf($handle, "%s", $str);
+
+$length = strlen($str);
+
+$flag = true;
+$some = [];
+
+for ($i=0; $i < $length; $i++) {
+    $index = ord($str[$i]) - ord('a');
+    if (isset($some[$index])) {
+        $some[$index] ++;
+    } else {
+        $some[$index] = 1;
+    }
+}
+
+if ($length % 2 == 0) {
+    foreach ($some as $a) {
+        if ($a % 2 !== 0) {
+            $flag = false;
+            break;
+        }
+    }
+} else {
+    $odd = 0;
+    $even = 0;
+    foreach ($some as $a) {
+        if ($a % 2 !== 0) {
+            $even ++;
+        } else {
+            $odd ++;
+        }
+    }
+
+    if ($even != 1 || $odd == $length - 1) {
+        $flag = false;
+    }
+}
+
+echo $flag ? "YES\n" : "NO\n";
diff --git a/string/5-gem-stones.cpp b/string/5-gem-stones.cpp
new file mode 100644
index 0000000..34af293
--- /dev/null
+++ b/string/5-gem-stones.cpp
@@ -0,0 +1,34 @@
+#include <iostream>
+#include <string>
+
+using namespace std;
+
+int main(int argc, char const *argv[])
+{
+    int n;
+    int count = 0;
+    int letter[26] = {0};
+    cin >> n;
+
+    for (int i = 0; i < n; ++i)
+    {
+        string str;
+        cin >> str;
+
+        for (int j = 0; j < str.length(); ++j)
+        {
+            if (letter[str[j] - 'a'] == i)
+                letter[str[j] - 'a'] ++;
+        }
+    }
+
+    for (int i = 0; i < 26; ++i)
+    {
+        if (letter[i] == n)
+            count ++;
+    }
+
+    cout << count << endl;
+
+    return 0;
+}
diff --git a/string/5-gem-stones.php b/string/5-gem-stones.php
new file mode 100644
index 0000000..9609a44
--- /dev/null
+++ b/string/5-gem-stones.php
@@ -0,0 +1,25 @@
+<?php
+
+$handle = fopen("php://stdin", "r");
+fscanf($handle, "%d", $N);
+
+for ($i=0; $i < 26; $i++) {
+    $some[$i] = 0;
+}
+
+for ($i=0; $i < $N; $i++) {
+    fscanf($handle, "%s", $str);
+
+    for ($j=0; $j < strlen($str); $j++) {
+        if ($some[ord($str[$j]) - ord('a')] == $i) {
+            $some[ord($str[$j]) - ord('a')] ++;
+        }
+    }
+}
+
+$count = 0;
+for ($i=0; $i < 26; $i++) {
+    if ($some[$i] == $N) $count ++;
+}
+
+echo $count . PHP_EOL;
diff --git a/string/6-make-it-anagram.cpp b/string/6-make-it-anagram.cpp
new file mode 100644
index 0000000..6839a5a
--- /dev/null
+++ b/string/6-make-it-anagram.cpp
@@ -0,0 +1,36 @@
+#include <iostream>
+#include <string>
+#include <cmath>
+
+using namespace std;
+
+int main(int argc, char const *argv[])
+{
+    string one;
+    string two;
+    int count = 0;
+
+    cin >> one >> two;
+
+    int some[26] = {0};
+    int other[26] = {0};
+
+    for (int i = 0; i < one.length(); ++i)
+    {
+        some[one[i] - 'a'] ++;
+    }
+
+    for (int i = 0; i < two.length(); ++i)
+    {
+        other[two[i] - 'a'] ++;
+    }
+
+    for (int i = 0; i < 26; ++i)
+    {
+        count += abs(some[i] - other[i]);
+    }
+
+    cout << count << endl;
+
+    return 0;
+}
diff --git a/string/6-make-it-anagram.php b/string/6-make-it-anagram.php
new file mode 100644
index 0000000..3cd6eb8
--- /dev/null
+++ b/string/6-make-it-anagram.php
@@ -0,0 +1,36 @@
+<?php
+
+$handle = fopen("php://stdin", "r");
+fscanf($handle, "%s", $one);
+fscanf($handle, "%s", $two);
+
+$some = [];
+$other = [];
+
+for ($i=0; $i < 26; $i++) {
+    $some[$i] = 0;
+    $other[$i] = 0;
+}
+
+for ($i=0; $i < strlen($one); $i++) {
+    $index = ord($one[$i]) - ord('a');
+
+    if (isset($some[$index])) {
+        $some[$index] ++;
+    } else{
+        $some[$index] = 0;
+    }
+}
+
+for ($i=0; $i < strlen($two); $i++) {
+    $index = ord($two[$i]) - ord('a');
+
+    $other[$index] ++;
+}
+
+$count = 0;
+for ($i=0; $i < 26; $i++) {
+    $count += abs($some[$i] - $other[$i]);
+}
+
+echo $count . PHP_EOL;
diff --git a/string/7-anagram.cpp b/string/7-anagram.cpp
new file mode 100644
index 0000000..532c425
--- /dev/null
+++ b/string/7-anagram.cpp
@@ -0,0 +1,44 @@
+#include <iostream>
+#include <string>
+#include <cmath>
+
+using namespace std;
+
+int main(int argc, char const *argv[])
+{
+    int T;
+    cin >> T;
+
+    while (T --) {
+        int count = 0;
+        int letter[26] = {0};
+        string s;
+        cin >> s;
+
+        int length = s.length();
+
+        if (length % 2 == 1) {
+            cout << -1 << endl;
+            continue;
+        }
+
+        for (int i = 0; i < length / 2; ++i)
+        {
+            letter[s[i] - 'a'] ++;
+        }
+
+        for (int i = length / 2; i < length; ++i)
+        {
+            letter[s[i] - 'a'] --;
+        }
+
+        for (int i = 0; i < 26; ++i)
+        {
+            count += abs(letter[i]);
+        }
+
+        cout << count / 2 << endl;
+    }
+
+    return 0;
+}
diff --git a/string/7-anagram.php b/string/7-anagram.php
new file mode 100644
index 0000000..965ca44
--- /dev/null
+++ b/string/7-anagram.php
@@ -0,0 +1,34 @@
+<?php
+
+$handle = fopen("php://stdin", "r");
+fscanf($handle, "%d", $T);
+
+while ($T --) {
+    fscanf($handle, "%s", $str);
+
+    if (strlen($str) % 2 == 1) {
+        echo "-1\n";
+        continue;
+    }
+
+    $count = 0;
+    $letter = [];
+    $length = strlen($str);
+    for ($i=0; $i < 26; $i++) {
+        $letter[$i] = 0;
+    }
+
+    for ($i=0; $i < $length / 2; $i++) {
+        $letter[ord($str[$i]) - ord('a')] ++;
+    }
+
+    for ($i=$length / 2; $i < $length; $i++) {
+        $letter[ord($str[$i]) - ord('a')] --;
+    }
+
+    for ($i=0; $i < 26; $i++) {
+        $count += abs($letter[$i]);
+    }
+
+    echo $count / 2 . PHP_EOL;
+}
diff --git a/string/8-two-string.cpp b/string/8-two-string.cpp
new file mode 100644
index 0000000..9c6fd43
--- /dev/null
+++ b/string/8-two-string.cpp
@@ -0,0 +1,38 @@
+#include <iostream>
+#include <string>
+
+using namespace std;
+
+int main(int argc, char const *argv[])
+{
+    int T;
+    cin >> T;
+
+    while (T --) {
+        bool exists = false;
+        string letters = "abcdefghijklmnopqrstuvwxyz";
+
+        string str1;
+        string str2;
+        cin >> str1 >> str2;
+
+        for (int i = 0; i < 26; ++i)
+        {
+            if (str1.find(letters[i]) != string::npos && str2.find(letters[i])  != string::npos) {
+                exists = true;
+                break;
+            }
+        }
+
+        if (exists)
+        {
+            cout << "YES\n";
+        }
+        else
+        {
+            cout << "NO\n";
+        }
+    }
+
+    return 0;
+}
diff --git a/string/8-two-string.php b/string/8-two-string.php
new file mode 100644
index 0000000..d6a471a
--- /dev/null
+++ b/string/8-two-string.php
@@ -0,0 +1,41 @@
+<?php
+
+$handle = fopen("php://stdin", "r");
+fscanf($handle, "%d", $T);
+
+while ($T --) {
+    fscanf($handle, "%s", $str1);
+    fscanf($handle, "%s", $str2);
+
+    // one
+    // $exists = false;
+    // $letter = [];
+    // for ($i=0; $i < 26; $i++) {
+    //     $letter[$i] = 0;
+    // }
+
+    // for ($i=0; $i < strlen($str1); $i++) {
+    //     $letter[ord($str1[$i]) - ord('a')] ++;
+    // }
+
+    // for ($i=0; $i < strlen($str2); $i++) {
+    //     $index = ord($str2[$i]) - ord('a');
+
+    //     if ($letter[$index] != 0) {
+    //         $exists = true;
+    //         break;
+    //     }
+    // }
+
+    // two
+    $exists = false;
+
+    foreach (range('a', 'z') as $letter) {
+        if (strpos($str1, $letter) !== false && strpos($str2, $letter) !== false) {
+            $exists = true;
+            break;
+        }
+    }
+
+    echo $exists ? "YES\n" : "NO\n";
+}
diff --git a/string/9-sherlock-and-anagrams.cpp b/string/9-sherlock-and-anagrams.cpp
new file mode 100644
index 0000000..c82bcc8
--- /dev/null
+++ b/string/9-sherlock-and-anagrams.cpp
@@ -0,0 +1,52 @@
+#include <iostream>
+#include <string>
+#include <map>
+#include <algorithm>
+
+using namespace std;
+
+int main(int argc, char const *argv[])
+{
+    int T;
+    cin >> T;
+
+    while (T --) {
+        string s;
+        cin >> s;
+        int length = s.length();
+
+        int step = 1;
+        map<string, int> anagrams;
+
+        while (step < length) {
+            for (int i = 0; i < length - step + 1; ++i)
+            {
+                string str = s.substr(i, step);
+                sort(str.begin(), str.end());
+
+                if (anagrams.find(str) != anagrams.end())
+                {
+                    anagrams[str] ++;
+                }
+                else
+                {
+                    anagrams[str] = 1;
+                }
+            }
+            step ++;
+        }
+
+        int count = 0;
+        map<string, int>::iterator it;
+        for (it = anagrams.begin(); it != anagrams.end(); it ++)
+        {
+            if (it->second >= 2) {
+                count += (it->second * (it->second - 1)) / 2;
+            }
+        }
+
+        cout << count << endl;
+    }
+
+    return 0;
+}
diff --git a/string/a.out b/string/a.out
new file mode 100755
index 0000000..baf813f
Binary files /dev/null and b/string/a.out differ