Added solution of problem BALONI from COCI

Author: jhonber

COCI/COCI-2015-216-Round#1/BALONI.cpp

@@ -0,0 +1,21 @@
+#include<bits/stdc++.h>
+using namespace std;
+
+int main() {
+  int n;
+  cin >> n;
+
+  int ans = 0;
+  map<int, int> mapa;
+  for (int i = 0; i < n; ++i) {
+    int a;
+    cin >> a;
+
+    if (mapa[a + 1] == 0) ans ++;
+    else mapa[a + 1] --;
+    mapa[a] ++;
+  }
+
+  cout << ans << endl;
+  return 0;
+}