why won't this C++ code work?
Posted: 2006-10-17 11:52pm
I need to take a few integers, put them through a function, and then round UP to the next integer (0.000001 = 1)
I wrote the following test program:
which I opened in Excel and compared with the decimal values to get:
it seems to be always rounding down?
Does anyone see what I'm doing wrong?
(compiler in use: Cygnus' CygWin g++ 2.91.57)
PS. it's in a rather rather large recursive algorithm, so clock cycles is a concern, which is why I'd rather not use something like:
(x/y%1)==0 ? return x/y : return x/y-(x/y%1);
I wrote the following test program:
Code: Select all
#include <iostream>
#include <cmath>
#include <fstream>
int main(){
ofstream data;
data.open("test.csv");
int test=0;
for(int i=10;i>0;i--){
for(int j=10;j>0;j--){
test=int(ceil(i/j)+.5);
data<<i<<","<<j<<","<<test<<endl;
}
}
data.close();
}Code: Select all
i j test decimal
5 5 1 1
5 4 1 1.25
5 3 1 1.666666667
5 2 2 2.5
5 1 5 5
4 5 0 0.8
4 4 1 1
4 3 1 1.333333333
4 2 2 2
4 1 4 4
3 5 0 0.6
3 4 0 0.75
3 3 1 1
3 2 1 1.5
3 1 3 3
2 5 0 0.4
2 4 0 0.5
2 3 0 0.666666667
2 2 1 1
2 1 2 2
1 5 0 0.2
1 4 0 0.25
1 3 0 0.333333333
1 2 0 0.5
1 1 1 1
Does anyone see what I'm doing wrong?
(compiler in use: Cygnus' CygWin g++ 2.91.57)
PS. it's in a rather rather large recursive algorithm, so clock cycles is a concern, which is why I'd rather not use something like:
(x/y%1)==0 ? return x/y : return x/y-(x/y%1);