PAT (Advanced Level) Practice 1060 Are They Equal

柔光的暖阳◎ 2023-06-24 11:24 23阅读 0赞

这题可以分两部，先求出要保留的数字部分，再求出指数部分，另外浮点数作为字符串处理时，一定要考虑前导0和末尾0，例如：000.00，0099.800。

给出一组比较容易错的数据：4 0000 0000.00 // YES 0.0000\*10^0

#include <iostream>
    #include <stdio.h>
    #include <string>
    using namespace std;
    string chop(string str, int n){//获取有效数据
        string result = str;
        int index = result.find(".");
        if(index != string::npos){
           result.erase(index,1);
        }
        while(result.length()>1 && result[0]=='0'){
            result.erase(0,1);
        }
         while(result.length() > n){
                result.erase(result.length()-1,1);
            }
            while(result.length() < n){
                result += "0";
            }
            return result;
    }
    
    int getP(string str){//获取指数
        string result = str;
        while(result.length()>2 && result[0]=='0' && result[1]!='.'){
            result.erase(0,1);
        }
        int index = result.find(".");
        if(index ==string::npos){
            if(result[0]=='0'){ 
                return 0;
            }else{
                return result.length();
            }
        }else{
            if(result[0]=='0'){
                int m = 0;
                while(index+1<result.length() && result[index+1]=='0'){
                    m--;
                    index++;
                }
                if(index+1>=result.length()){
                    return 0;
                }else{ 
                    return m;
                }
            }else{ 
                return index;
            }
        }
    }
    
    int main()
    {
        int n,len_a,len_b;
        string a,b;
        cin>>n>>a>>b;
        len_a = a.length();
        len_b = b.length();
        int pa,pb;//计算a b是十的多少次方
        pa = getP(a);
        pb = getP(b);
        string ra=chop(a,n);
        string rb=chop(b,n);
        if(ra == rb && pa == pb){
            cout<<"YES"<<" "<<"0."<<ra<<"*10^"<<pa<<endl;
        }else{
            cout<<"NO"<<" "<<"0."<<ra<<"*10^"<<pa<<" "<<"0."<<rb<<"*10^"<<pb<<endl;
        }
        return 0;
    }