Codility MaxCounters

struct Results solution(int N, int A[], int M) {
    struct Results result;
    // write your code in C99
    int * c = calloc(N, sizeof(int));
    int max = 0;
    int latestMax = 0;
    int i = 0;
    int idx = 0;
    
    for (; i < M; i++) {
     
        if (A[i] == N + 1) {
            max = latestMax;
        } else {
         
            idx = A[i] - 1;
            if (c[idx] < max) {
                c[idx] = max;
            }
            
            c[idx]++;
            
            if (c[idx] > latestMax) {
                latestMax = c[idx];
            }
        }
        
    }
    
    for (i = 0; i < N; i++) {
        if (c[i] < max) {
            c[i] = max;
        }
    }
    
    result.C = c;
    result.L = N;
    return result;
}