此算法空间复杂度较高，寻找最长不重复子串，核心代码（s是序列，v是s的缓存）

int len = m, ans = 0, start = -1;
for (int j = 0; j < len; j++)
{
    if (v[s[j]] > start) // Slding Window
        start = v[s[j]];
    v[s[j]] = j;
    ans = max(ans, j - start);
}

AC代码

#include <bits/stdc++.h>
using namespace std;

int v[2010];
int aa[2010];
int s[2010];

int main(void)
{
    int n, m, anss = 0;
    cin >> n >> m;
    for (int i = 0; i < n; i++)
    {
        for (int j = 0; j < m; j++)
            scanf("%d", &s[j]);

        memset(v, -1, sizeof(v));
        int len = m, ans = 0, start = -1;
        for (int j = 0; j < len; j++)
        {
            if (v[s[j]] > start) // Slding Window
                start = v[s[j]];
            v[s[j]] = j;
            ans = max(ans, j - start);
        }

        aa[i] = ans;
        anss = max(anss, aa[i]);
    }
    cout << anss << endl;
    for (int i = 0; i < n; i++)
        if (aa[i] == anss)
            cout << i + 1 << ' ';
    return 0;
}

本来是用vector的，但是vector太慢了（笑哭

纠正个错字：sliding

看到了这个分享我才知道有"滑动窗口算法" 感谢大爹!!（AC辽