sort_complex.c

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <math.h>

#define MAX_N 100

typedef struct {
	double real;
	double imag;
	double abs;
} complex;

void generate(complex *c, const int n, const int max);
void print_complex(const complex *c, const int n);
int compare(const complex *c1, const complex *p2);

int debug = 0;

int main(int argc, char **argv) {
	if (argc < 3) {
		printf("Usage\n\t%s <N> <MAX>\n\nN: the number of complex numbers (<%d)\nMAX: the maximum real or imaginary component which will be genaerated\n", argv[0], MAX_N);
		return -1;
	} else {
		int n, max;
		complex c[MAX_N];

		n = atoi(argv[1]);
		max = atoi(argv[2]);
		if (argc == 4)
			debug = 1;

		generate(c, n, max);

		if (debug) {
			print_complex(c, n);
			printf("\n");
		}

		qsort(c, n, sizeof(complex), (int (*)(const void*, const void*))compare);

		print_complex(c, n);

		return 0;
	}
}

void generate(complex *c, const int n, const int max) {
	int i;
	srand(time(NULL));
	for (i=0; i<n; i++) {
		c[i].real = rand() % max;
		c[i].imag = rand() % max;
		c[i].abs = sqrt((c[i].real)*(c[i].real) + (c[i].imag)*(c[i].imag));
	}
}

void print_complex(const complex *c, const int n) {
	int i;
	for (i=0; i<n; i++) {
		printf("(%lf, %lf) %lf\n", c[i].real, c[i].imag, c[i].abs);
	}
}

int compare(const complex *c1, const complex *c2) {
	if (c1->abs < c2->abs)
		return -1;
	else if (c1->abs > c2->abs)
		return 1;
	return 0;
}