POJ 1129.Channel Allocation

题目:http://poj.org/problem?id=1129

AC代码(C++):

#include <iostream>#include <algorithm>#include <stdio.h>#include <vector>#include <queue>#include <math.h>#include <string>#include <string.h>#include <bitset>#define INF 0xfffffff#define MAXN 100105using namespace std;int n;bool map[30][30];int chan[30];void dfs(int x){if(x==n){return;}chan[x] = 1;for(int i = 0; i < n; i++){if(map[x][i]&&chan[i]==chan[x]){chan[x]++;i = -1;}}dfs(x+1);}int main(){while(cin>>n){if(n==0)break;memset(map,false,sizeof(map));memset(chan,0,sizeof(chan));char str[50];int u,v;for(int i = 0; i < n; i++){scanf("%s",&str);u = str[0] - 'A';for(int j = 2; j < strlen(str); j++){v = str[j] - 'A';map[u][v] = true;map[v][u] = true;}}for(int i = 0; i < n; i++)dfs(i);int max = 0;for(int i = 0; i < n; i++){if(chan[i]>max)max = chan[i];}if(max==1)cout<<"1 channel needed.\n";else cout<<max<<" channels needed.\n";}}

总结: 水题.