solving some problems from atcoder

Atcoder/atcoder_problemset/abc345_a.cpp

@@ -0,0 +1,20 @@
+#include <bits/stdc++.h>
+
+int main(void) {
+
+    std::string s; std::cin >> s;
+    std::unordered_map<char, int> unmap;
+
+    for(int i = 0; i < (int)s.length(); ++i)
+        unmap[s[i]]++;
+
+    if(s[0] == '<' and s[s.length()-1] == '>') {
+        if(unmap['<'] > 1 || unmap['>'] > 1) {
+            std::cout << "No" << std::endl;
+        } else
+            std::cout << "Yes" << std::endl;
+    } else
+        std::cout << "No" << std::endl;
+
+}
+

Atcoder/atcoder_problemset/abc345_b.cpp

@@ -0,0 +1,16 @@
+#include <bits/stdc++.h>
+
+typedef long long ll;
+
+int main(void) {
+
+    // Can't use function ceil, because has decimal errors
+
+    ll n; std::cin >> n;
+    if((n+9) < 0 && ((n+9) % 10 != 0)) 
+        std::cout << (n+9) / 10-1 << std::endl;
+    else {
+        std::cout << (n+9) / 10 << std::endl;
+    } 
+
+}