我用归并写的这个题，之前一直TLE，反复修改还是TLE，想不明白了，最后用AC的和TLE的相对比，发现错误出在申请内存上面，我把int* b = new int[r-l+1]写成int* b = new int[10000]则必定超时，真是让我闻所未闻，这是什么原因
可以提交试下：
#include <cstdio>
#include <algorithm>

using namespace std;
__int64 res;
int a[10010];

void Merge(int *a, int l, int r)
{
    if(l < r)
    {
        int c = (l+r)/2;
        Merge(a, l, c);
        Merge(a, c+1, r);
        int i = l, j = c+1, x = 0;
        int *b;
        b = (int *)malloc(10000*sizeof(int));
        while (i <= c && j <= r)
        {
            if (a[i] <= a[j]) b[x++] = a[i++];
            else
            {
                b[x++] = a[j++];
                res += (c-i+1);
            }
        }
        while (i <= c) b[x++] = a[i++];
        while (j <= r) b[x++] = a[j++];
        for (x = 0, i = l; i <= r; x++, i++) a[i] = b[x];
        free(b);
    }
}

int main()
{
    int n, i, cnt = 1, k;
    scanf("%d", &k);
    while (k--)
    {
        scanf("%d", &n);
        res = 0;
        for (int i = 1; i <= n; i++) scanf("%d", &a[i]);
        Merge(a, 1, n);
        printf("Scenario #%d:\n", cnt++);
        printf("%d\n\n", res);
    }
    return 0;
}