poj_1789

来源：互联网发布：iphone7换铃声软件编辑：程序博客网时间：2024/06/07 09:24

题意就是让你求一个最小生成树，一共有n个点，每两个点之间的距离就是字符串相对应位置上不同的字母个数，由题可知，这是一个完全图。建好图后，我们任意选择一个起点(这里我们选择0点)，跑一遍Prim就能够计算出最小生成树的长度。

#include<stdio.h>#include<iostream>#include<string>#include<string.h>#include<algorithm>#include<iomanip>#include<vector>#include<time.h>#include<queue>#include<stack>#include<iterator>#include<math.h>#include<stdlib.h>#include<limits.h>#include<map>//#define ONLINE_JUDGE#define eps 1e-10#define INF 0x7fffffff#define inf 0x3f3f3f3f#define FOR(i,a) for((i)=0;i<(a);(i)++)#define MEM(a) (memset((a),0,sizeof(a)))#define sfs(a) scanf("%s",a)#define sf(a) scanf("%d",&a)#define sfI(a) scanf("%I64d",&a)#define pf(a) printf("%d\n",a)#define pfI(a) printf("%I64d\n",a)#define pfs(a) printf("%s\n",a)#define sfd(a,b) scanf("%d%d",&a,&b)#define sft(a,b,c)scanf("%d%d%d",&a,&b,&c)#define for1(i,a,b) for(int i=(a);i<b;i++)#define for2(i,a,b) for(int i=(a);i<=b;i++)#define for3(i,a,b)for(int i=(b);i>=a;i--)#define MEM1(a) memset(a,0,sizeof(a))#define MEM2(a) memset(a,-1,sizeof(a))#define ll __int64const double PI=acos(-1.0);template<class T> T gcd(T a,T b){return b?gcd(b,a%b):a;}template<class T> T lcm(T a,T b){return a/gcd(a,b)*b;}template<class T> inline T Min(T a,T b){return a<b?a:b;}template<class T> inline T Max(T a,T b){return a>b?a:b;}using namespace std;int n,m;int s;#define N 2010int mp[N][N];char ch[N][10];int getDis(char *a,char *b){    int len = strlen(a);    int dif=0;    for(int i=0;i<len;i++)        if(a[i]!=b[i]) dif++;    return dif;}int vis[N];int dis[N];int Prim(){    for(int i=0;i<n;i++)        dis[i] = mp[0][i];    dis[0]=0;    memset(vis,0,sizeof vis);    int ans=0;    for(int i=0;i<n;i++){        int mmin = INF;        int flag = -1;        for(int j=0;j<n;j++)            if(!vis[j]&&mmin>dis[j])                mmin = dis[flag=j];        if(flag==-1) break;        ans += mmin;        vis[flag] = 1;        for(int j=0;j<n;j++)            if(!vis[j] && dis[j]>mp[flag][j])                dis[j] = mp[flag][j];    }    return ans;}int main(){#ifndef ONLINE_JUDGE    freopen("in.txt","r",stdin);//  freopen("out.txt","w",stdout);#endif    int kas = 1;    while(scanf("%d",&n)!=EOF && n){        for(int i=0;i<n;i++)            sfs(ch[i]);        for(int i=0;i<n;i++){            for(int j=i;j<n;j++){                mp[i][j] = mp[j][i] = getDis(ch[i],ch[j]);            }        }        printf("The highest possible quality is 1/%d.",Prim());    }return 0;}

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