Kadane's Algorithm

Algo/KMPStringMatching.java

@@ -0,0 +1,51 @@
+
+public class KMP {
+
+    public static void main(String[] args) {
+        String s = "ABCMNBCJDMVBC";
+        String pat = "BC";
+
+        int n = s.length();
+        int m = pat.length();
+        int[] lps = getLps(pat, m);
+        int i=0; int j=0;
+        while(i<n && j<m) {
+            if(s.charAt(i)==pat.charAt(j)) {
+                i++; j++;
+            }
+            if(j==m) {
+                System.out.println("found pattern at =" + (i-j));
+                j = lps[j-1];
+            }
+
+            if(i<n && j<m && s.charAt(i) != pat.charAt(j)) {
+                if(j != 0)
+                    j = lps[j-1];
+                else
+                    i++;
+            }
+        }
+    }
+
+    public static int[] getLps(String pat, int m) {
+        int[] lps = new int[m];
+        int i=1, len=0;
+        lps[0] = 0;
+        while (i<m) {
+            if(pat.charAt(i)==pat.charAt(len)) {
+                len++;
+                lps[i] = len;
+                i++;
+            }else {
+                if(len > 0)
+                    len = lps[len-1];
+                else{
+                    lps[i] = len;
+                    i++;
+                }
+            }
+        }
+        return lps;
+
+    }
+}

Algo/KadaneLargestSumConitnuousSubarray.java

@@ -0,0 +1,27 @@
+import java.io.*;
+import java.util.*;
+
+class KadaneLargestSumConitnuousSubarray
+{
+    public static void main (String[] args)
+    {
+        int [] a = {-2, -3, 4, -1, -2, 1, 5, -3};
+        System.out.println("Maximum contiguous sum is " + maxSubArraySum(a));
+    }
+
+    static int maxSubArraySum(int arr[])
+    {
+        int size = arr.length;
+        int max_so_far = Integer.MIN_VALUE, max_ending_here = 0;
+
+        for (int i = 0; i < size; i++)
+        {
+            max_ending_here = max_ending_here + arr[i];
+            if (max_so_far < max_ending_here)
+                max_so_far = max_ending_here;
+            if (max_ending_here < 0)
+                max_ending_here = 0;
+        }
+        return max_so_far;
+    }
+}