得物笔试

有道算法题是求两个字符串中的最小字串，求大佬帮忙看下是哪里出错了一直提交0%？我自己的测试集都过了，实在不明白为什么会0%

class LongestSubstring {
    public:
        int findLongest(string A, int n, string B, int m) {
            // write code here
            int aLeft,aRight;
            int maxLen = 0;
            for(aLeft = 0,aRight = 0; aLeft < n; aLeft++){
                for(int i = 0; i < m; i++){
                    if(aRight == n){
                        if(maxLen < aRight-aLeft-1){
                            maxLen = aRight-aLeft-1;
                        }
                        aRight = aLeft;
                        break;
                    }
                    if(A[aRight] == B[i]){
                        aRight++;
                    }
                    else{
                        if(maxLen < aRight-aLeft){
                            maxLen = aRight-aLeft;
                        }
                        aRight = aLeft;
                    }
                }
            }
            return maxLen;
        }
    };