HackerEarth Diamonds problem solution

In this HackerEarth Diamonds problem solution, Roman loved diamonds. Monica decided to give him a beautiful gift on Valentine’s Day. Her idea of diamonds was different though. She lit up all the windows of her rectangular building with N floors and M windows on each floor, with 2 shapes – / or . According to her, a diamond was made when such a shape was created:

/

/

we have Given the shape of lights in all the windows, help Roman count the number of diamonds formed.

Note: The components of the diamond should be adjacent to each other.

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

char a[1024][1024];

int main() {
  int t;cin>>t;
  while(t--) {
    int n,m;
    cin>>n>>m;
    assert(n>=2 && n<=1000);
    assert(m>=2 && m<=1000);
    for(int i=0;i<n;i++) {
      for(int j=0;j<m;j++) {
        cin>>a[i][j];
      }
    }
    int cnt=0;
    for(int i=0;i<n-1;i++) {
      for(int j=0;j<m-1;j++) {
        if(a[i][j]=='/' && a[i][j+1]=='\' && a[i+1][j]=='\' && a[i+1][j+1]=='/') {
          cnt++;
        }
      }
    }
    cout<<cnt<<"n";
  }
}