PAT-A1060 Are They Equal 题目内容及题解
If a machine can save only 3 significant digits, the float numbers 12300 and 12358.9 are considered equal since they are both saved as 0.123×10^5 with simple chopping. Now given the number of significant digits on a machine and two float numbers, you are supposed to tell if they are treated equal in that machine.
Input Specification:
Each input file contains one test case which gives three numbers N, A and B, where N (<100) is the number of significant digits, and A and B are the two float numbers to be compared. Each float number is non-negative, no greater than 10^100, and that its total digit number is less than 100.
Output Specification:
For each test case, print in a line YES if the two numbers are treated equal, and then the number in the standard form 0.d[1]...d[N]*10^k (d[1]>0 unless the number is 0); or NO if they are not treated equal, and then the two numbers in their standard form. All the terms must be separated by a space, with no extra space at the end of a line.
Note: Simple chopping is assumed without rounding.
Sample Input 1:
3 12300 12358.9
Sample Output 1:
YES 0.123*10^5
Sample Input 2:
3 120 128
Sample Output 2:
NO 0.120*10^3 0.128*10^3
题目大意
题目给定机器上的有效数字和两个浮点数的数量,要求输出两个数字在给定的有效数字下存储结果是否一致。截断数字时只需要简单截断,无需四舍五入。
解题思路
- 用字符串形式读入两组待对比数据,并将其处理为目标形式;
- 对比其是否一致,并按照格式输出结果;
- 返回零值。
代码
#include<iostream>
#include<string>
using namespace std;
int N,e;
string Deal(string a){
int k=0;
int num=0;
string res;
e=0;
while(a.length()>0&&a[0]=='0'){
a.erase(a.begin());
}
if(a[0]=='.'){
a.erase(a.begin());
while(a.length()>0&&a[0]=='0'){
a.erase(a.begin());
e--;
}
}else{
while(k<a.length()&&a[k]!='.'){
k++;
e++;
}
if(k<a.length()){
a.erase(a.begin()+k);
}
}
if(a.length()==0){
e=0;
}
while(num<N){
if(num<a.length()){
res+=a[num];
}else{
res+='0';
}
num++;
}
return res;
}
int main(){
string A,B;
int e1;
cin>>N>>A>>B;
A=Deal(A);
e1=e;
B=Deal(B);
if(A==B&&e1==e){
cout<<"YES 0."<<A<<"*10^"<<e<<endl;
}else{
cout<<"NO 0."<<A<<"*10^"<<e1<<" 0."<<B<<"*10^"<<e<<endl;
}
return 0;
}
运行结果