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題解：先求出最小生成樹，用倍增LCA求出不在最小生成樹中的邊的答案，同時再用這個答案它去更新最小生成樹中的邊的答案。為了提高更新這一操作的效率，列舉有序（從小到大）的邊集，更新過的用並查集連在一起（由於從小到大，小的最優，下條邊一定不會再次更新它們），下一次直接往上跳即可。

#include<cstdio>
#include<cstring>
#include<iostream>
#include<algorithm>
using namespace std;
const int MAXN=2e5+2,INF=0x3f3f3f3f
 
;
struct kruskal {
    int u,v,w,id;
    friend bool operator <(const kruskal &a,const kruskal &b) {
        return a.w<b.w;
    }
}kr[MAXN];
int head[MAXN],edge;
struct EDGE {
    int v,nxt,w,id;
}e[MAXN<<1];
bool inm[MAXN];
int n,m;
int fa[MAXN];
int ans[MAXN];
int anc[MAXN][19
 
],mx[MAXN][19],dep[MAXN],up[MAXN];
inline int read() {
    int x=0;char c=getchar();
    while (c<'0'||c>'9') c=getchar();
    while (c>='0'&&c<='9') x=x*10+c-'0',c=getchar();
    return x;
}
inline void adde(int u,int v,int w,int id) {
    e[edge].nxt=head[u],e[edge].v=v,e[edge].id=id,e[edge].w=w,head[u]=edge++;
    e[edge].nxt=head[v],e[edge].v=u,e[edge].id=id,e[edge].w=w,head[v]=edge++;
}
int
 
 find(int x) {
    return fa[x]==x?x:fa[x]=find(fa[x]);
}
void dfs(int p,int f,int d) {
    dep[p]=dep[f]+1,anc[p][0]=f,mx[p][0]=d;
    for (int i=1;i<=18;++i) anc[p][i]=anc[anc[p][i-1]][i-1],mx[p][i]=max(mx[p][i-1],mx[anc[p][i-1]][i-1]);
    for (int i=head[p];~i;i=e[i].nxt) {
        int v=e[i].v;
        if (v==f) continue;
        up[v]=e[i].id,dfs(v,p,e[i].w);
    }
}
int lca(int x,int y,int &d) {
    d=0;if (dep[x]<dep[y]) x^=y^=x^=y;
    for (int i=18;i>=0;--i) {
        if (dep[anc[x][i]]>=dep[y]) {
            d=max(d,mx[x][i]);
            x=anc[x][i];
        }
    }
    if (x==y) return x;
    for (int i=18;i>=0;--i) {
        if (anc[x][i]^anc[y][i]) {
            d=max(d,max(mx[x][i],mx[y][i]));
            x=anc[x][i],y=anc[y][i];
        }
    }
    d=max(d,max(mx[x][0],mx[y][0]));
    return anc[x][0];
}
void modify(int x,int lca,int w) {
    x=find(x);
    while (dep[x]>dep[lca]) {
        ans[up[x]]=min(ans[up[x]],w);
        int y=find(anc[x][0]);
        fa[x]=y;
        x=find(x);
    }
}
int main() {
//  freopen("codeforces 827D.in","r",stdin);
    while (~scanf("%d%d",&n,&m)) {
        memset(head,-1,sizeof(head));
        memset(inm,0,sizeof(inm));
        edge=0;
        for (register int i=1;i<=n;++i) fa[i]=i;
        for (register int i=1;i<=m;++i) kr[i].id=i,kr[i].u=read(),kr[i].v=read(),kr[i].w=read();
        sort(kr+1,kr+m+1);
        int blo=n;
        for (register int i=1;i<=m&&blo>1;++i) {
            int u=kr[i].u,v=kr[i].v;
            u=find(u),v=find(v);
            if (u^v) {
                fa[u]=v,inm[i]=true,--blo;
                adde(kr[i].u,kr[i].v,kr[i].w,kr[i].id);
            }
        }
        dfs(1,0,0);
        memset(ans,INF,sizeof(ans));
        for (register int i=1;i<=n;++i) fa[i]=i;
        for (register int i=1;i<=m;++i) {
            if (inm[i]) continue;
            int u=kr[i].u,v=kr[i].v,f=lca(u,v,ans[kr[i].id]);
            --ans[kr[i].id];
            modify(u,f,kr[i].w-1);
            modify(v,f,kr[i].w-1);
        }
        for (int i=1;i<=m;++i)
            printf("%d\n",ans[i]==INF?-1:ans[i]);
    }
    return 0;
}