求最大公共子串（的长度）

#include <stdio.h>
#include <string.h>

#define N 50
int f(const char* s1, const char* s2)
{
    int a[N][N];//矩阵
    int len1 = strlen(s1);
    int len2 = strlen(s2);
    int i,j;

    memset(a,0,sizeof(int)*N*N);
    int max = 0;
    for(i=1; i<=len1; i++){
        for(j=1; j<=len2; j++){
            if(s1[i-1]==s2[j-1]) {//s1的第i个和s2的第j个相等
                a[i][j] =a[i-1][j-1]+1;  //很重要
                if(a[i][j] > max) max = a[i][j];
            }
        }
    }
    for(i=1;i<=len1;i++){
    for(j=1;j<=len2;j++)
     cout<<a[i][j]<<" ";
     cout<<endl;
}
    return max;
}

int main()
{
    printf("%d\n", f("abcdkkk", "baabcdadabc"));
    return 0;
}