POJ 1521 Entropy

Huffman树：

题目链接：POJ1521

#include<stdio.h>#include<string.h>#include<queue>using namespace std;int t[100],len;char c[1000];int huffman(){    int a,b,c,sum=0;    priority_queue<int,vector<int>,greater<int> >q;//priority_queue<int,vector<int>,greater<int> > q;    for(int i=65;i<100;i++) {        if(t[i]>0)            q.push(t[i]);    }    while(q.size()>1)    {        a=q.top();q.pop();        b=q.top();q.pop();        c=a+b;        sum+=c;        q.push(c);    }    return sum?sum:len;}int main(){    int sum;    while(scanf("%s",c)!=EOF)    {       if(strcmp(c,"END")==0)            break;       memset(t,0,sizeof t);       len=strlen(c);       for(int i=0;i<len;i++)           t[c[i]]++;       sum=huffman();       printf("%d %d %.1f\n",len*8,sum,(double)len*8/sum);    }    return 0;}