poj1417 True Liars

边带权比较好做,然后dp方案

#include <algorithm>
#include <iostream>
#include <cstring>
#include <cstdio>
#include <vector>
using namespace std;
int n, pu, pv, uu, vv, fa[605], gx[605], cnt, bel1[605], bel2[605], dp[605][305];
char ss[15];
vector<int> vec[605][2], ans;
int myfind(int x){
	if(x==fa[x])	return x;
	int t=myfind(fa[x]);
	gx[x] ^= gx[fa[x]];
	fa[x] = t;
	return t;
}
int main(){
	while(scanf("%d %d %d", &n, &pu, &pv)!=EOF){
		if(!n && !pu && !pv)	break;
		for(int i=1; i<=pu+pv; i++){
			fa[i] = i;
			gx[i] = 0;
		}
		for(int i=1; i<=cnt; i++)	vec[i][0].clear(), vec[i][1].clear();
		ans.clear();
		cnt = 0;
		for(int i=1; i<=n; i++){
			scanf("%d %d %s", &uu, &vv, ss);
			int p=myfind(uu), q=myfind(vv);
			if(p==q)	continue;
			gx[p] = gx[uu] ^ gx[vv] ^ (ss[0]=='n');
			fa[p] = q;
		}
		for(int i=1; i<=pu+pv; i++)
			if(fa[i]==i){
				bel1[i] = ++cnt;
				bel2[i] = 0;
				vec[cnt][0].push_back(i);
			}
		for(int i=1; i<=pu+pv; i++)
			if(fa[i]!=i){
				int p=myfind(i);
				int q=gx[i]^bel2[p];
				vec[bel1[p]][q].push_back(i);
			}
		memset(dp, 0, sizeof(dp));
		dp[0][0] = 1;
		for(int i=1; i<=cnt; i++)
			for(int j=0; j<=pu; j++){
				if(j>=vec[i][0].size())	dp[i][j] += dp[i-1][j-vec[i][0].size()];
				if(j>=vec[i][1].size())	dp[i][j] += dp[i-1][j-vec[i][1].size()];
			}
		if(dp[cnt][pu]!=1)	printf("no
");
		else{
			for(int i=cnt; i>=1; i--){
				int p=vec[i][0].size(), q=vec[i][1].size();
				if(dp[i-1][pu-p]==1){
					pu -= p;
					for(int j=0; j<p; j++)	ans.push_back(vec[i][0][j]);
				}
				else{
					pu -= q;
					for(int j=0; j<q; j++)	ans.push_back(vec[i][1][j]);
				}
			}
			sort(ans.begin(), ans.end());
			int p=ans.size();
			for(int i=0; i<p; i++)	printf("%d
", ans[i]);
			printf("end
");
		}
	}
	return 0;
}
原文地址:https://www.cnblogs.com/poorpool/p/8494449.html