Can anyone help how to fix runtime error in this code?

Task is to determine the count of substrings, where the count of digit C is exactly P

Input Format: The first line contains integer t denoting the number of test cases, For the next 2*t (2 lines for each test case), the first line contains two integers P and C, and the second line contains a string. Let us denote the string by symbol s. Constraints:

1<=t<=10

1<=P,|s|<=1000000

0<=C<=9

Time Limit: 1 second Output Format: For each test case, the first and only line of output contains the answer as described in task.

Sample Input 1:

2

1 2

212

4 5

55555

Sample Output 1:

4

2

Explanation: For First test case: {2}, {2,1}, {1,2}, {2} are the substrings that contains digit 2 exactly 1 time.

For Second test case: {5,5,5,5}, {5,5,5,5} are the substrings that contains digit 5 exactly 4 times .

I am getting runtime error in this

        using namespace std; 
          
        
        int countSubString(string s, char c, int k) 
        { 
        
            int leftCount = 0, rightCount = 0; 
          
           
            int left = 0, right = 0; 
          
            int freq = 0; 
          
            int result = 0, len = s.length(); 
          
            
            while (s[left] != c && left < len) { 
                left++; 
                leftCount++; 
            } 
          
            
            right = left + 1; 
            while (freq != (k - 1) && (right - 1) < len) { 
                if (s[right] == c) 
                    freq++; 
                right++; 
            } 
          
          
            while (left < len && (right - 1) < len) { 
          
                
                while (s[left] != c && left < len) { 
                    left++; 
                    leftCount++; 
                } 
          
            
                while (right < len && s[right] != c) { 
                    if (s[right] == c) 
                        freq++; 
                    right++; 
                    rightCount++; 
                } 
          
                
                result = result + (leftCount + 1) * (rightCount + 1); 
          
                
                freq = k - 1; 
          
            
                leftCount = 0; 
                rightCount = 0; 
          
                left++; 
                right++; 
            } 
          
            return result; 
        } 
          
        // Driver code 
        int main() 
        { 
            int t;
            cin>>t;
            while(t--){
                
            
            string s;
            
            cin>> s[1000000];
            char c;
                cin>>c;
            int k;
                cin>>k;
          
            cout << countSubString(s, c, k); 
          
            return 0; 
            }
        }