POJ 1041 John’s trip歐拉路

很簡單的一道求歐拉路的題。用矩陣的話最好用關聯矩陣，因為可能兩點間連好幾條路，用vector存的話記著要sort

#include<cstdio>#include<string.h>#include<stdlib.h>#include<stack>using namespace std; int map[46][2000],d[46],m;bool vis[2000];stack<int>st;int max(int a,int b){return a>b?a:b;}void euler(int u){int i;for(i=1;i<=m;i++)if(map[u][i] && !vis[i]){vis[i]=1;euler(map[u][i]);st.push(i);}}int main(){int x,y,z,i,j;while(scanf("%d %d",&x,&y) && !(x==0 && y==0)){m=0;memset(map,0,sizeof(map));memset(d,0,sizeof(d));memset(vis,0,sizeof(vis));scanf("%d",&z);d[x]++,d[y]++;map[x][z]=y,map[y][z]=x,m=max(m,z);int first=x>y?y:x;while(scanf("%d %d",&x,&y) && !(x==0 && y==0)){d[x]++,d[y]++;scanf("%d",&z);m=max(m,z);map[x][z]=y,map[y][z]=x;}for(i=1;i<=45;i++)if(d[i]%2)break;if(i<=45){printf("Round trip does not exist.\n");}else{euler(first);bool f=1;while(!st.empty()){if(f){printf("%d",st.top());f=0;}elseprintf(" %d",st.top());st.pop();}printf("\n");}}}