UVA 437 The Tower of Babylon

#include<stdio.h>
#include<string.h>
#include<stdlib.h>
#define MAXD 110
int N, f[MAXD], a[5][MAXD], r[MAXD];
int cmp(const void *_p, const void *_q)
{
    int *p = (int *)_p;
    int *q = (int *)_q;
    return a[0][*p] * a[1][*p] - a[0][*q] * a[1][*q];
}
int init()
{
    int i;
    scanf("%d", &N);
    if(!N)
        return 0;
    N *= 3;
    for(i = 0; i < N; i ++)
    {
        scanf("%d%d%d", &a[0][i], &a[1][i], &a[2][i]);
        i ++;
        a[2][i] = a[0][i - 1], a[0][i] = a[1][i - 1], a[1][i] = a[2][i - 1];
        i ++;
        a[2][i] = a[0][i - 1], a[0][i] = a[1][i - 1], a[1][i] = a[2][i - 1];
    }
    return 1;
}
void solve()
{
    int i, j, ri, rj, temp, max;
    for(i = 0; i < N; i ++)
        r[i] = i;
    qsort(r, N, sizeof(r[0]), cmp);
    for(i = 0; i < N; i ++)
        f[i] = a[2][r[i]];
    for(i = 1; i < N; i ++)
    {
        ri = r[i];
        for(j = 0; j < i; j ++)
        {
            rj = r[j];
            if((a[0][rj] < a[0][ri] && a[1][rj] < a[1][ri]) || (a[0][rj] < a[1][ri] && a[1][rj] < a[0][ri]))
            {
                temp = f[j] + a[2][ri];
                if(temp > f[i])
                    f[i] = temp;
            }
        }
    }
    max = 0;
    for(i = 0; i < N; i ++)
        if(f[i] > max)
            max = f[i];
    printf("%d
", max);
}
int main()
{
    int t = 0;
    while(init())
    {
        printf("Case %d: maximum height = ", ++ t);
        solve();
    }
    return 0;
}