【HDOJ】2124 Repair the Wall

经典贪心，这样的贪心AC了很多了。

#include <stdio.h>

#define MAXNUM 605

int length[MAXNUM];

int comp(const void *a, const void *b) {
    return *(int *)b - *(int *)a;
}

int main() {
    int n, l;
    int i, tmp, cnt;

    while (scanf("%d %d", &l, &n) != EOF) {
        for (i=0; i<n; ++i)
            scanf("%d", &length[i]);

        qsort(length, n, sizeof(int), comp);

        tmp = l;
        cnt = 0;
        for (i=0; i<n; ++i) {
            if (length[i] < tmp) {
                tmp -= length[i];
                cnt++;
            } else {
                cnt++;
                tmp = 0;
                break;
            }
        }
        if (tmp)
            printf("impossible\n");
        else
            printf("%d\n", cnt);
    }

    return 0;
}