DFS 专题 Beat

HINT 误导人，水题。

# include <cstdio>
# include <cstring>

# define N 15 + 5

int n, ans;
int f[N][N];
bool vis[N];

void dfs(int cur, int cnt, int t)
{
    if (cnt > ans) ans = cnt;
    for (int i = 0; i < n; ++i) if (vis[i] == false && f[cur][i] >= t)
    {
        vis[i] = true;
        dfs(i, cnt+1, f[cur][i]);
        vis[i] = false;
    }
}

void init(void)
{
    for (int i = 0; i < n; ++i)
    for (int j = 0; j < n; ++j)
        scanf("%d", &f[i][j]);
    memset(vis, false, sizeof(vis));
}

void solve(void)
{
    ans = 1;
    vis[0] = true;
    dfs(0, 1, 0);
    printf("%d\n", ans);
}

int main()
{
    while (~scanf("%d", &n))
    {
        init();
        solve();
    }

    return 0;
}

/**/