[uva] 10474 - Where is the Marble?

http://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&page=show_problem&problem=1415

这个水的要死的题...哪能看出来是回溯, 为啥刘汝佳大神要放到回溯分类里...

#include <cstdio>
#include <vector>
#include <algorithm>

using namespace std;
int main(int argc, const char * argv[])
{
    int N = 0, Q = 0;
    int id = 1;
    while (scanf("%d%d", &N, &Q)) {
        if (N == 0 && Q == 0) {
            break;
        }
        vector<int> arr(N);
        vector<int> q(Q);
        for (unsigned int i = 0; i < N; ++i) {
            scanf("%d", &arr[i]);
        }
        for (unsigned int i = 0; i < Q; ++i) {
            scanf("%d", &q[i]);
        }
        sort(arr.begin(), arr.end());
        printf("CASE# %d:\n", id++);
        for (unsigned int i = 0; i < Q; ++i) {
            vector<int>::iterator re = find(arr.begin(), arr.end(), q[i]);
            if (re != arr.end()) {
                printf("%d found at %d\n", q[i], int(re - arr.begin() + 1));
            } else {
                printf("%d not found\n", q[i]);
            }
        }
    }
    return 0;
}