HDU 2986 Ballot evaluation（精度问题）

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题意 ： 给你n个人名，每个名后边跟着一个数，然后m个式子，判断是否正确。

思路 ：算是一个模拟吧，但是要注意浮点数容易丢失精度，所以要好好处理精度，不知道多少人死在精度上，不过我实在是不怎么会处理精度，所以我就让那个数变为字符串输入然后在处理，相当于乘上10，但是直接乘上10，数容易变，不知道的自己可以试一下。

#include <iostream>
#include <string.h>
#include <stdio.h>
#include <string>
#include <map>
#include <algorithm>
 
using namespace std;
string name[] ;
string score ;
char ch[] ;
int yun ;
int main()
{
    int p,g ,x,m;
    scanf("%d %d",&p,&g) ;
    map<string,int >mp ;
    for(int i =  ; i < p ; i++)
    {
        cin>>name[i]>>score ;
        m =  ;
        int len = score.size() ;
        m += score[len-]-'' ;
        int j;
        for(j =  ; j < len ; j++)
        if(score[j] == '.') break ;
        int n =  ;
      //  printf("%d*\n",j) ;
        for(int k = j- ; k >=  ; k--)
        {
            m += (score[k]-'')*n ;
            n = n* ;
        }
        mp[name[i]] = m ;
       // printf("#%d#\n",mp[name[i]]) ;
    }
    for(int i =  ; i <= g ; i++)
    {
        int sum =  ;
        while(true)
        {
            scanf("%s",ch) ;
            if(ch[] == '=' || ch[] == '>'||ch[] == '<')
           {
               if(ch[] == '=')
               yun =  ;
               else if(ch[] == '>' && ch[] == '=' )
               yun =  ;
               else if(ch[] == '<' && ch[] == '=')
               yun =  ;
               else if(ch[] == '>')
               yun =  ;
               else if(ch[] == '<')
               yun =  ;
               break ;
           }
            if(ch[] != '+')
            sum += mp[ch] ;
        }
        scanf("%d",&x) ;
        x *=  ;
       // printf("%d %d\n",sum,x) ;
        if(yun == )
        {
            if(sum > x)
            printf("Guess #%d was correct.\n",i) ;
            else printf("Guess #%d was incorrect.\n",i) ;
        }
        if(yun == )
        {
            if(sum < x)
            printf("Guess #%d was correct.\n",i) ;
            else printf("Guess #%d was incorrect.\n",i) ;
        }
        if(yun == )
        {
            if(sum == x)
            printf("Guess #%d was correct.\n",i) ;
            else printf("Guess #%d was incorrect.\n",i) ;
        }
        if(yun == )
        {
            if(sum >= x)
            printf("Guess #%d was correct.\n",i) ;
            else printf("Guess #%d was incorrect.\n",i) ;
        }
        if(yun == )
        {
            if(sum <= x)
            printf("Guess #%d was correct.\n",i) ;
            else printf("Guess #%d was incorrect.\n",i) ;
        }
    }
    return  ;
}