getLCSSlen

#include<bits/stdc++.h>
using namespace std;
///****************
#define NMAX 1001
char a[NMAX], b[NMAX];
int dp[NMAX][NMAX];
int getLCSSlen(char a[], char b[]) {
    int n = strlen(a + 1);
    int m = strlen(b + 1);
    int ans = 0;
    assert(n < NMAX && m < NMAX);
    for (int i = 1; i <= n; i++)
        for (int j = 1; j <= m; j++)
            if (a[i] == b[j]) {
                dp[i][j] = dp[i - 1][j - 1] + 1;//else =0;
                ans = max(ans, dp[i][j]);
            }
    return ans;
}

int main() {
    cin >> (a + 1) >> (b + 1);
    std::cerr << getLCSSlen(a, b) << '\n';//9
    return 0;
}