Small_Triangles_Large_Triangles

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

struct triangle
{
	int a;
	int b;
	int c;
};

typedef struct triangle triangle;
double area_squared(triangle* tr) {
    double p = (tr->a + tr->b + tr->c) / 2.0;
    return p * (p - tr->a) * (p - tr->b) * (p - tr->c);
}

int cmp_t(triangle* tr1, triangle* tr2) {
    double a1 = area_squared(tr1);
    double a2 = area_squared(tr2);
    return (a1 > a2) - (a1 < a2);
}

void sort_by_area(triangle* tr, int n) {
    // insertion sort
    for (int i = 1; i < n; i++) {
        int j = i;
        triangle pivot = tr[i];
        while (j > 0 && cmp_t(&tr[j-1], &pivot) > 0) {
            tr[j] = tr[j-1];
            j--;
        }
        tr[j] = pivot;      
    }
}
int main()
{
	int n;
	scanf("%d", &n);
	triangle *tr = malloc(n * sizeof(triangle));
	for (int i = 0; i < n; i++) {
		scanf("%d%d%d", &tr[i].a, &tr[i].b, &tr[i].c);
	}
	sort_by_area(tr, n);
	for (int i = 0; i < n; i++) {
		printf("%d %d %d\n", tr[i].a, tr[i].b, tr[i].c);
	}
	return 0;
}