输入正整数a,b,c,输出a/b的小数形式,精确到小数后c位。(提示:使用循环)

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#include<bits/stdc++.h>
using namespace std;
#define MAX_LEN 100
char ans[MAX_LEN+10];
int main()
{
memset(ans,0,sizeof(ans));
int a,b,c;
int anslen;

cin>>a>>b>>c;


sprintf(ans,"%d.",a/b);//打印整数部分及小数点
ans[MAX_LEN+8]=anslen=strlen(ans);
a%=b;
for (int i=0; i<c; i++)
{


sprintf(ans+anslen+i,"%d",a*10/b);
a=a*10%b;
}
ans[MAX_LEN+9]= anslen=strlen(ans);
int flags=0;//进位标志
for (int i=ans[MAX_LEN+9]-1; i>ans[MAX_LEN+8]-1; i--)
{
if(flags)
{
if(ans[i]=='9')
{
ans[i]='0';
flags=1;
}
else//停止进位
{
ans[i]++;
flags=0;
break;
}

}
if(ans[i]=='9')
{
ans[i]='0';
flags=1;

}
else if(ans[i]>='5')
{
ans[i]++;
flags=0;
break;
}


}
for (int i=ans[MAX_LEN+8]-2; i>=0; i--)
{
if(flags)
{
if(ans[i]=='9')
{
ans[i]='0';
flags=1;
}
else//停止进位
{
ans[i]++;
flags=0;
break;
}

}
if(ans[i]=='9')
{
ans[i]='0';
flags=1;

}
else if(ans[i]>='5')
{
ans[i]++;
flags=0;
break;
}


}
printf("%s",ans);

return 0;
}