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来源：互联网发布：访客网络限速多少合适编辑：程序博客网时间：2024/05/05 15:01

#include <cstdio>#include <iostream>#include <algorithm>#include <queue>#include <cmath>#include <cstring>#include <stack>#include <set>#include <map>#include <vector>using namespace std;#define INF 0x2fffffff#define LL long long#define MAX(a,b) ((a)>(b))?(a):(b)#define MIN(a,b) ((a)<(b))?(a):(b)struct edge{    int x,y,n,f;}; edge es[600015];int head[100005];int ans[600005];int d[100005];int vis[100005];int cnt = 0;void add(int x,int y){    es[cnt].x = x;    es[cnt].y = y;    es[cnt].n = head[x];    es[es[cnt].n].f = cnt;    es[cnt].f = -1;    head[x] = cnt++;}void euler(int u){    while(head[u]!=-1){        int v = head[u];        if(v&1)            ans[v^1] = 0;        else            ans[v] = 1;        head[u] = es[v].n;        if(es[v].n!=-1){            es[es[v].n].f = es[v].f;        }        if(es[v^1].f == -1)            head[es[v].y] = es[v^1].n;        else            es[es[v^1].f].n = es[v^1].n;        if(es[v^1].n != -1){            es[es[v^1].n].f = es[v^1].f;        }        d[es[v].y] --;        d[es[v].x] --;        u = es[v].y;    }}int main(){    int t;    cin >> t;    while(t--){        int n,m;        scanf("%d%d",&n,&m);        cnt = 0;        for(int i = 0;i <= n;i++){            head[i] = -1;            d[i] = 0;        }        for(int i = 0;i < m;i++){            int x,y;            scanf("%d%d",&x,&y);            d[x]++;            d[y]++;              add(x,y);            add(y,x);        }        for(int i = 1;i <= n;i++){            if(d[i]&1){                euler(i);            }        }        for(int i = 1;i <= n;i++){            if(d[i] > 0){                euler(i);            }        }        for(int t = 0;t < m;t++){            int i = t<<1;             printf("%d\n",ans[i]);        }    }        return 0;}

从奇度数点开始搜，肯定会终结于一个奇度数的点，这样就可以找到一条路，但是同时要记得删边，这样才能达到O(n+m）的复杂度

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