【POJ】2828 Buy Tickets

线段树+逆序插入。

#include <stdio.h>
#include <string.h>

#define MAXN 200005
#define lson l, mid, rt<<1
#define rson mid+1, r, rt<<1|1

int space[MAXN<<2];
int nums[MAXN];
int pi[MAXN], vi[MAXN];
int pos;

void build(int l, int r, int rt) {
    int mid;
    space[rt] = r - l +1;
    if (l == r)
        return ;
    mid = (l+r)>>1;
    build(lson);
    build(rson);
}

void update(int p, int l, int r, int rt) {
    int mid;
    --space[rt];
    if (l == r) {
        pos = l;
        return ;
    }
    mid = (l+r) >> 1;
    if (space[rt<<1] >= p)
        update(p, lson);
    else {
        p -= space[rt<<1];
        update(p, rson);
    }
}

int main() {
    int i, n;

    while (scanf("%d", &n) != EOF) {
        build(1, n, 1);
        for (i=1; i<=n; ++i)
            scanf("%d %d", &pi[i], &vi[i]);
        for (i=n; i>0; --i) {
            update(pi[i]+1, 1, n, 1);
            nums[pos] = vi[i];
            //printf("pos=%d
", pos);
        }
        printf("%d", nums[1]);
        for (i=2; i<=n; ++i)
            printf(" %d", nums[i]);
        printf("
");
    }

    return 0;
}