USACO Riding Fences 欧拉回路

参考: http://www.cppblog.com/Ylemzy/articles/100050.html

注意path数组长度为1025（edge的个数），刚开始弄成501（vertex个数）结果test 8 爆栈了

/*  ID: wangxin12  PROG: fence LANG: C++  */#include <iostream>#include <fstream>#define MAX 505#define Max(a,b) (a > b ? a : b)#define Min(a,b) (a < b ? a : b)using namespace std;int map[MAX][MAX], num[MAX], path[1050]; //map¹¹Í¼£¬ num¼ÇÔØÿ¸öµã¶ÈÊý£¬path¼ÇÔØ·¾¶int minn, maxn, index = 0; //ÒòΪÌâÄ¿ÖÐvertex²»´Ó1¿ªÊ¼£¬ÒªÔÚ¶ÁÈëÊý¾ÝµÄʱºò¼ÇÔØvertexµÄ×îС×î´óÖµvoid circle(int x) {int i;if(num[x]) {do {for(i = minn; i <= maxn; i++) {if(map[x][i]) break;   }                              //find the smallest neighbormap[x][i]--, map[i][x]--;num[x]--, num[i]--;           //delete this edgecircle(i);  //} while ( num[x] );path[index++] = x;}else path[index++] = x;}void deal() {int i;for(i = minn; i <= maxn; i++) {if(num[i] % 2 == 1) {circle(i);return;}}circle(minn);}int main() {ifstream fi("fence.in");ofstream fo("fence.out");//intputint n, from, to, i;fi>>n;for(i = 1, minn = 500, maxn = 1; i <= n; i++) {fi>>from>>to;map[from][to]++, map[to][from]++;num[from]++, num[to]++;if( minn > Min(from, to) ) minn = Min(from, to);if( maxn < Max(from, to) ) maxn = Max(from, to);}deal();//outputfor(int j = index - 1; j >= 0; j--) {fo<<path[j]<<endl;}fi.close();fo.close();return 0;}