连续最大子字符串 Longest Common Substring，longestsubstring

连续最大子字符串 Longest Common Substring，longestsubstring

题目

LintCode 79. Longest Common Substring

子字符串和子序列相比，需要连续，因此和上一道题会有一些不同，需要取每个连续子串长度的最大值。

代码

class Solution {
public:
    /**
     * @param A: A string
     * @param B: A string
     * @return: the length of the longest common substring.
     */
    int longestCommonSubstring(string &A, string &B) {
        int alen = A.size(), blen = B.size();
        if (!alen || !blen) {
            return 0;
        }
        int a[1000][1000] = {0}, t_max = 0;
        int i, j;
        for (i = 1; i <= alen; i++) {
            for (j = 1; j <= blen; j++) {
                if (A[i-1] == B[j-1]) {
                    a[i][j] = a[i-1][j-1] + 1;
                } else {
                    t_max = max(max(a[i-1][j], a[i][j-1]), t_max);
                }
            }
        }


        return max(t_max, a[i-1][j-1]);
    }
};