hdu 3577 线段树

题意：一列经过1000000个站点的火车上最多同时乘坐 K 个人，有 Q 个乘客按照题目给出的顺序去买票，输出所有购票成功的乘客

做法：RMQ线段树 + 区间更新

#include "bits/stdc++.h"
using namespace std;
#define lson l, m, rt<<1
#define rson m + 1, r, rt<<1|1
const int MAXN = 1000010;
const int INF = 0x3f3f3f3f;

struct Node
{
    int Max;

    int add;
    bool same;
    int sameVal;
}node[MAXN<<2];

inline void PushDown(int rt, int segLen)
{
    if (node[rt].same) {
        node[rt<<1].Max = node[rt].sameVal;
        node[rt<<1|1].Max = node[rt].sameVal;

        node[rt<<1].same = node[rt<<1|1].same = true;
        node[rt<<1].sameVal = node[rt<<1|1].sameVal = node[rt].sameVal;
        node[rt].same = false;
    }
    if(node[rt].add) {
        node[rt<<1].Max += node[rt].add;
        node[rt<<1|1].Max += node[rt].add;

        node[rt<<1].add += node[rt].add;
        node[rt<<1|1].add += node[rt].add;
        node[rt].add = 0;
    }
}

inline void PushUp(int rt)
{
    node[rt].Max = max(node[rt<<1].Max, node[rt<<1|1].Max);
}

void Build(int l, int r, int rt)
{
    node[rt].same = false;
    node[rt].add = 0;

    if (l == r) {
//        scanf("%d", &node[rt].Max);
        node[rt].Max = 0;
        return ;
    }
    int m = (l + r)>>1;
    Build(lson);
    Build(rson);

    PushUp(rt);
}

void UpdateAdd(int p, int add, int l, int r, int rt)
{
    if (l == r) {
        node[rt].Max += add;
        return ;
    }
    PushDown(rt, r - l + 1);
    int m = (l + r) >> 1;
    if (p <= m) {
        UpdateAdd(p, add, lson);
    }
    else {
        UpdateAdd(p, add, rson);
    }

    PushUp(rt);
}

void UpdateModify(int p, int newVal, int l, int r, int rt)
{
    if (l == r) {
        node[rt].Max = newVal;
        return ;
    }
    PushDown(rt, r - l + 1);
    int m = (l + r) >> 1;
    if (p <= m) {
        UpdateModify(p, newVal, lson);
    }
    else {
        UpdateModify(p, newVal, rson);
    }

    PushUp(rt);
}

void UpdateAdd_Seg(int L, int R, int add, int l, int r, int rt)
{
    if (L <= l && r <= R) {
        node[rt].Max += add;

        node[rt].add += add;
        return ;
    }

    PushDown(rt, r - l + 1);
    int m = (l + r) >> 1;
    if (L <= m) {
        UpdateAdd_Seg(L, R, add, lson);
    }
    if (R > m) {
        UpdateAdd_Seg(L, R, add, rson);
    }

    PushUp(rt);
}

void UpdateModify_Seg(int L, int R, int newVal, int l, int r, int rt)
{
    if (L <= l && r <= R) {
        node[rt].Max = newVal;

        node[rt].same = true;
        node[rt].sameVal = newVal;
        return ;
    }

    PushDown(rt, r - l + 1);
    int m = (l + r) >> 1;
    if (L <= m) {
        UpdateModify_Seg(L, R, newVal, lson);
    }
    if (R > m) {
        UpdateModify_Seg(L, R, newVal, rson);
    }

    PushUp(rt);
}


int Query(int L, int R, int l, int r, int rt)
{
    if (L <= l && r <= R) {
        return node[rt].Max;
    }
    PushDown(rt, r - l + 1);
    int m = (l + r) >> 1;
    int ans = -INF;
    if (L <= m) {
        ans = max(ans, Query(L, R, lson));
    }
    if (R > m) {
        ans = max(ans, Query(L, R, rson));
    }
    return ans;
}

int n, m;
int POS, ADD, NewVal, L, R;

int main()
{
    int t, T, K, Q;
    scanf("%d", &T);
    for (t = 1; t <= T; ++t) {
        Build(1, 1000000, 1);
        scanf("%d%d", &K, &Q);
        int index = 0;
        printf("Case %d:
", t);
        while (Q--) {
            ++index;
            scanf("%d%d", &L, &R);
            if(Query(L, R - 1, 1, 1000000, 1) < K) {
                printf("%d ", index);
                UpdateAdd_Seg(L, R - 1, 1, 1, 1000000, 1);
            }
        }
        printf("

");
    }
}