【HDOJ】1908 Double Queue

双端队列+二分。

#include <cstdio>

#define MAXN 1000005

typedef struct {
    int id;
    int p;
} node_st;

node_st que[MAXN];
int rear = 0,front = 0;

void Insert(int id, int p) {
    int l = front, r = rear, mid;

    while ( l <= r) {
        mid = (l+r)>>1;
        if (que[mid].p == p)
            break;
        if (que[mid].p < p)
            l = mid+1;
        else
            r = mid - 1;
    }
    while (mid<rear && que[mid].p <= p)
        ++mid;
    for (int i=rear-1; i>=mid; --i)
        que[i+1] = que[i];
    que[mid].id = id;
    que[mid].p = p;
    rear++;
}

int main() {
    int c, id, p;

    while (scanf("%d", &c)!=EOF && c) {
        if (c == 1) {
            scanf("%d %d", &id, &p);
            Insert(id, p);
        } else {
            if (rear == front)
                printf("0\n");
            else {
                if (c == 2)
                    printf("%d\n", que[--rear].id);
                else
                    printf("%d\n", que[front++].id);
            }
        }
    }

    return 0;
}