time difference

[C++ Programming]

My program compiles and runs but it is not working properly, it gives me as time differnce = 0... Pleaes take a look and help..

v#include
#include
#include

using namespace std;

/*
*
*/
int main(int argc, char** argv) {

time_t start;
time_t end;
double timeDifference;
int a = 1500;
int b = 23;
int integerDivision;
float c = 1500.0000;
float d = 23.0000;
float floatDivision;

cout