面试OR笔试10——小数转字符串

1 题目及要求

1.1 题目描述

2 解答

2.1 代码

string dtos_m(double x, int n =0){
string res;
if(x<0) {
res.push_back('-');
x = -x;
}
int xint = (int) x, base(10);
x -= xint;
if(!xint) res.push_back('0');
else{
while(base <= xint) base*=10;
for( int bk(base/10);bk;bk/=10){
res.push_back('0'+xint/bk);
xint = xint % bk;
}
}
base = 1;
n = n < 0 ? 0 : n;
for (int k1(0); k1 < n; ++k1) {
x *= 10;
base *= 10;
}
x+=0.5;
xint = (int) x;
if(!xint) return res;
res.push_back('.');
for( int bk(base/10);xint;bk/=10){
res.push_back('0'+xint/bk);
xint = xint % bk;
}
return res;
}