hdu 3415 Max Sum of MaxKsubsequence

http://acm.hdu.edu.cn/showproblem.php?pid=3415

　　不难的单调队列，不过刚开始的时候开的队列不够大，所以数组越界了。不过最不解的是hdu返回的是wa而不是runtime error，搞到我以为是单调队列写错什么了，所以不停debug，debug了好多组数据，最终才想到队列的大小是会超出n的，于是改过来以后就ac了！

　　时间相当理想，才46ms！

下面是我的代码：

#include <cstdio>
#include <cstring>
#include <cstdlib>

const int maxn = 100001;
const int inf = 0x7fffffff;
int q[maxn << 1], ind[maxn << 1], qh, qt;
int begin, end, sv[maxn];

void scan(int &n){
    char ch;

    while ((ch = getchar()) != '-' && ('0' > ch || ch > '9'));
    if (ch != '-'){
        n = ch - '0';
        while ((ch = getchar()) >= '0' && ch <= '9')
            n = n * 10 + ch - '0';
    }
    else{
        n = 0;
        while ((ch = getchar()) >= '0' && ch <= '9')
            n = n * 10 + '0' - ch;
    }
}

int main(){
#ifndef ONLINE_JUDGE
    freopen("in", "r", stdin);
#endif
    int N;
    int n, k, sum, tmp, maxsum, ci;

    scan(N);
    while (N--){
        scan(n); scan(k);

        qh = sum = begin = q[0] = 0;
        qt = 1;
        ind[0] = -1;
        maxsum = -inf;
        end = n;

        for (int i = 0; i < n; i++){
            scan(sv[i]);
            sum += sv[i];
            if (i - ind[qh] > k) qh++;

            tmp = sum - q[qh];
            if (tmp > maxsum){
                maxsum = tmp;
                begin = ind[qh] + 1;
                end = i;
            }
            while (qh < qt && q[qt - 1] >= sum) qt--;
            q[qt] = sum;
            ind[qt++] = i;
        }

        for (int i = 0; i < k; i++){
            ci = i + n;

            sum += sv[i];
            if (ci - ind[qh] > k) qh++;

            tmp = sum - q[qh];
            if (tmp > maxsum){
                maxsum = tmp;
                begin = ind[qh] + 1;
                end = ci;
            }
            while (qh < qt && q[qt - 1] >= sum) qt--;
            q[qt] = sum;
            ind[qt++] = ci;
        }

        printf("%d %d %d\n", maxsum, begin % n + 1, end % n + 1);
    }

    return 0;
}

——written by Lyon