Problem:
Score : 200 points

Problem Statement

We have a string S of length N consisting of uppercase English letters.

How many times does ABC occur in S as contiguous subsequences (see Sample Inputs and Outputs)?

Constraints

3 \leq N \leq 50

S consists of uppercase English letters.

Input

Input is given from Standard Input in the following format:

N
S

Output

Print number of occurrences of ABC in S as contiguous subsequences.

Sample Input 1

10
ZABCDBABCQ

Sample Output 1

2

Two contiguous subsequences of S are equal to ABC: the 2-nd through 4-th characters, and the 7-th through 9-th characters.

Sample Input 2

19
THREEONEFOURONEFIVE

Sample Output 2

0

No contiguous subsequences of S are equal to ABC.

Sample Input 3

33
ABCCABCBABCCABACBCBBABCBCBCBCABCB

Sample Output 3

5

Solution in C++14 (GCC 5.4.1) (judge verdict: Wrong Answer)

#include <bits/stdc++.h>
using namespace std;

int main()
{
  long x,i,sum,h,c;
  sum=0;
  h=0;
  cin >> x;  
  
  char s[x];
  for(i=0;i<x;i++)
  {
    cin >>s[i];
    if(s[i]=='A'&&h==0)
    {
      c=i;
      h=1;
    }else if(s[i]=='B'&&h==1&&(c+1)==i)
    {
      h=2;
    }else if(s[i]=='C'&&h==2&&(c+2)==i)
    {
      h=0;
      sum=sum+1;
    }
    else
    {
       if(s[i]=='A'&&h==0)
    {
      c=i;
      h=1;
    }else 
       { h=0;}
    }
    
  }
  cout << sum <<endl;
  
  return 0;
  
}