洛谷代码雀食用不来（恼

洛谷原题是这个

有点不一样，望大佬修改一下可以AC




#include <cstdio>
#include <cstring>
#include <algorithm>

typedef long long ll;
constexpr int N = 100005;

ll f[N],g[N];
int F[N],G[N],fa[N];

int find(int x) {
    return x == fa[x] ? x : fa[x] = find(fa[x]);
}

void solve() {
    int n,m;
    scanf("%d %d",&n,&m);
    memset(f,127,sizeof(f));
    memset(g,127,sizeof(g));
    for(int i = 1;i <= n;++i)
        fa[i] = i;
    for(int i = 1;i <= m;++i) {
        int u,v;
        scanf("%d %d",&u,&v);
        u = find(u),v = find(v);
        if(u == v) continue;
        fa[u] = v;
    }
    int r1 = find(1),rn = find(n);
    f[r1] = 0,g[rn] = 0;
    int cntF = 0,cntG = 0;
    for(int i = 1;i <= n;++i) {
        int u = find(i);
        if(u == r1) F[++cntF] = i;
        else if(u == rn) G[++cntG] = i;
    }
    for(int i = 1;i <= n;++i) {
        int u = find(i);
        if(u != r1) {
            int pre = std::upper_bound(F + 1,F + cntF + 1,i) - F - 1;
            f[u] = std::min(f[u],(ll)(i - F[pre]) * (i - F[pre]));
            if(pre < cntF) {
                ++pre;
                f[u] = std::min(f[u],(ll)(i - F[pre]) * (i - F[pre]));
            }
        }
        if(u != rn) {
            int nxt = std::upper_bound(G + 1,G + cntG + 1,i) - G;
            g[u] = std::min(g[u],(ll)(i - G[nxt]) * (i - G[nxt]));
            if(nxt > 1) {
                --nxt;
                g[u] = std::min(g[u],(ll)(i - G[nxt]) * (i - G[nxt]));
            }
        }
    }
    ll ans = (ll)(n - 1ll) * (n - 1ll);
    for(int i = 1;i <= n;++i) {
        int u = find(i);
        ans = std::min(ans,f[u] + g[u]);
    }
    printf("%lld\n",ans);
}

int main() {
    int T;
    scanf("%d",&T);
    while(T--) solve();
    return 0;
}