cf160D. Edges in MST(最小生成树 桥)

#include<bits/stdc++.h>
#define Pair pair<int, int>
#define MP(x, y) make_pair(x, y)
#define fi first
#define se second
using namespace std;
const int MAXN = 2e5 + 10;
inline int read() {
    char c = getchar(); int x = 0, f = 1;
    while(c < '0' || c > '9') {if(c == '-') f = -1; c = getchar();}
    while(c >= '0' && c <= '9') x = x * 10 + c - '0', c = getchar();
    return x * f;
}
int N, M;
vector<Pair> v[MAXN];
struct Edge {
    int u, v, w, f, id;
    bool operator < (const Edge &rhs) const {
        return w < rhs.w;
    }
}E[MAXN];
int dfn[MAXN], low[MAXN], tot, fa[MAXN], ans[MAXN];
void tarjan(int x, int fa) {//这里的fa表示边的编号
    dfn[x] = low[x] = ++tot;
    for(int i = 0, to, id; i < v[x].size(); i++) {
        if((id = v[x][i].se) == fa) continue;
        to = v[x][i].fi;
        if(!dfn[to]) {
            tarjan(to, id), low[x] = min(low[x], low[to]);
            if(low[to] > dfn[x]) E[id].f = 2;
        }
        else low[x] = min(low[x], dfn[to]);
    }
}

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

int main() {
    N = read(), M = read();
    for(int i = 1; i <= N; i++) fa[i] = i;
    for(int i = 1; i <= M; i++) {
        int x = read(), y = read(), z = read();
        E[i] = (Edge) {x, y, z, 0, i};
    }
    sort(E + 1, E + M + 1);
    int nxt;
    for(int i = 1; i <= M; i = nxt + 1) {
        nxt = i + 1;
        for(; E[i].w == E[nxt].w; nxt++); nxt--;
        for(int j = i; j <= nxt; j++) {
            int x = find(E[j].u), y = find(E[j].v);
            if(x == y) continue;
            v[x].push_back(MP(y, j));
            v[y].push_back(MP(x, j)); 
            E[j].f = 1;//maybe
        }
        for(int j = i; j <= nxt; j++) {
            int x = find(E[j].u), y = find(E[j].v);
            if(x == y || dfn[x]) continue;
            tarjan(x, -1);
        }
        for(int j = i; j <= nxt; j++) {
            int x = find(E[j].u), y = find(E[j].v);
            if(x == y) continue;
            v[x].clear(); v[y].clear();
            dfn[x] = 0; dfn[y] = 0;
            fa[x] = y;
        }
    }
    for(int i = 1; i <= M; i++) ans[E[i].id] = E[i].f;
    for(int i = 1; i <= M; i++) {
        if(ans[i] == 0) puts("none");
        else if(ans[i] == 1) puts("at least one");
        else puts("any");
    }
    return 0;
}
/*

*/