UVA 10131 Is Bigger Smarter?

UVA_10131

    这个题目首先可以把大象按体重升序排列，然后求一个IQ的最长下降子序列即可。

#include<stdio.h>
#include<string.h>
#include<stdlib.h>
#define MAXD 1010
int N, w[MAXD], q[MAXD], f[MAXD], r[MAXD], p[MAXD];
int cmp(const void *_p, const void *_q)
{
    int *p = (int *)_p;
    int *q = (int *)_q;
    return w[*p] - w[*q];
}
void printresult(int i)
{
    if(p[i] != -1)
        printresult(p[i]);
    printf("%d\n", r[i] + 1);
}
void solve()
{
    int i, j, k, max;
    for(i = 0; i < N; i ++)
    {
        r[i] = i;
        f[i] = 1;
    }
    memset(p, -1, sizeof(p));
    qsort(r, N, sizeof(r[0]), cmp);
    for(i = 1; i < N; i ++)
        for(j = 0; j < i; j ++)
        {
            if(w[r[j]] == w[r[i]])
                break;
            if(q[r[j]] > q[r[i]] && f[j] + 1 > f[i])
            {
                f[i] = f[j] + 1;
                p[i] = j;
            }
        }
    max = 0;
    for(i = 0; i < N; i ++)
        if(f[i] > max)
        {
            max = f[i];
            k = i;
        }
    printf("%d\n", max);
    printresult(k);
}
int main()
{
    N = 0;
    while(scanf("%d%d", &w[N], &q[N]) == 2)
        N ++;
    solve();
    return 0;
}