test for NDEBUG

#include <stdio.h>

#include <stdlib.h>

#define NDEBUG

#include <assert.h>

#include <math.h>

int main(void)

{

    float fa, fb, fc;

    puts("intput fa and fb, 0 0 to stop.");

    while (2 == scanf("%f %f", &fa, &fb) && (fa || fb) != 0)

    {

          fc = fa * fa - fb * fb;

          assert(fc >= 0);   

          printf("the answer is %f\n", sqrt(fc));

          puts("the nexe numbers:");

    }

    puts("Done");

    system("pause");

    return 0;

}