SmallTrianglesLargeTriangles.cpp

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

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

typedef struct triangle triangle;
int area(triangle t) {
    return((t.a+t.b+t.c)*(t.a+t.b-t.c)*(t.a+t.c-t.b)*(t.b+t.c-t.a)); 
}
void sort_by_area(triangle* tr, int n) {
	for(int i = 0; i < n - 1; i ++) 
        for(int j = i + 1; j < n; j ++)
            if(area(tr[i]) > area(tr[j])) {
                triangle t = tr[i];
                tr[i] = tr[j];
                tr[j] = t;
            }
}

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;
}