多校1007 Naive Operations

》》点击进入原题测试《《

思路：好像是第一次这么印象深刻的写线段树，说实话，这个题确实很有意思，值得学习。

看了大神讲解视频，但是自己写的还是超时了。

参考来自 https://blog.csdn.net/yiqzq/article/details/81211652 个人认为可以作为模板

#include <bits/stdc++.h>
#include <iostream>
#include <cstdio>
#include <algorithm>
#include <cstring>
#include <queue>
#include <vector>
#include <stack>
#include <set>
#include <cctype>
#define eps 1e-8
#define INF 0x3f3f3f3f
#define MOD 1e9+7
#define PI acos(-1)
#define lson l,m,rt<<1
#define rson m+1,r,rt<<1|1
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
const int maxn = 1e5 + ;

int n, q;
int MIN[maxn << ];//记录区间最小值
int lazy[maxn << ];//延迟标记减法
int ans[maxn << ];//记录答案数量
int b[maxn << ];//记录b数组

//线段树基本操作,pushup和pushdown
void pushup(int rt) {
    MIN[rt] = min(MIN[rt << ], MIN[rt <<  | ]);
    ans[rt] = ans[rt << ] + ans[rt <<  | ];
}

void pushdown(int rt) {
    if(lazy[rt]) {
        lazy[rt << ] += lazy[rt];
        lazy[rt <<  | ] += lazy[rt];
        MIN[rt << ] -= lazy[rt];
        MIN[rt <<  | ] -= lazy[rt];
        lazy[rt] = ;
    }
}
//建树
void build(int l, int r, int rt) {
    lazy[rt] = ;
    ans[rt] = ;
    if(l == r) {
        scanf("%d", &b[rt]);
        MIN[rt] = b[rt];
        return ;
    }
    int m = (l + r) >> ;
    build(lson);
    build(rson);
    pushup(rt);
}
//区间更新,需要注意当NIN减为0的时候,要ans++并且重新将b的值赋给MIN
void updata(int L, int R, int l, int r, int rt) {
    if(L <= l && R >= r) {
        MIN[rt]--;
        if(MIN[rt]) {
            lazy[rt]++;
            return;
        } else {
            if(l == r) {
                ans[rt]++;
                MIN[rt] = b[rt];
                return;
                /*血的教训,这个return不能放大括号外面,因为如果递归到某个节点MIN是0
                但是又不是叶子节点,那么还是需要继续递归直到找到叶子节点为止
                */
            }

        }
    }
    pushdown(rt);
    int m = (l + r) >> ;
    if(L <= m) updata(L, R, lson);
    if(R > m) updata(L, R, rson);
    pushup(rt);
}
//查询
int query(int L, int R, int l, int r, int rt) {
    if(L <= l && R >= r) {
        return ans[rt];
    }
    pushdown(rt);
    int m = (l + r) >> ;
    int sum = ;
    if(m >= L) sum += query(L, R, lson);
    if(m < R) sum += query(L, R, rson);
    return sum;
}
int main() {
    while(~scanf("%d%d", &n, &q)) {
        build(, n, );
        for(int i = ; i <= q; i++) {
            char op[];
            int a, b;
            scanf("%s%d%d", op, &a, &b);
            if(op[] == 'q') {
                printf("%d\n", query(a, b, , n, ));
            } else {
                updata(a, b, , n, );
            }
        }
    }
    return ;
}

复制来的代码

#include<queue>
#include<string>
#include<cstring>
#include<iostream>
#include<algorithm>

using namespace std;

#define lson l,m,rt<<1
#define rson m+1,r,rt<<1|1
const int maxn = 1e5 + ;

int add[maxn << ];
int tree[maxn << ];
int MAX[maxn << ];
int a[maxn];

void build(int l, int r,int rt)
{

    add[rt] = ;
    MAX[rt] = (int)-1e9;
    tree[rt] = ;

    if (l == r){
        add[rt] = ;
        tree[rt] = ;
        MAX[rt] = -a[l];
        return;
    }
    int m = (l + r) >> ;
    build(lson);
    build(rson);
    tree[rt] = tree[rt << ] + tree[rt <<  | ];
    MAX[rt] = max(MAX[rt << ], MAX[rt <<  | ]);
}
void PushDown(int rt)
{
    if (add[rt]){
        add[rt << ] += add[rt];
        add[rt <<  | ] += add[rt];
        MAX[rt << ] += add[rt];
        MAX[rt <<  | ] += add[rt];
        add[rt] = ;
    }
}
void update1(int L, int R, int l, int r, int rt)
{
    if (L <= l&&r <= R){
        add[rt]++;
        MAX[rt]++;
        return;
    }
    PushDown(rt);
    int m = (l + r) >> ;
    if (L <= m)update1(L, R, lson);
    if (R > m)update1(L, R, rson);
    tree[rt] = tree[rt << ] + tree[rt <<  | ];
    MAX[rt] = max(MAX[rt << ], MAX[rt <<  | ]);
}
void update2(int L, int R, int l, int r, int rt)
{
    if (l == r){

        if (MAX[rt] >= ){

            tree[rt]++;
            MAX[rt] = -a[l];
        }
        return;
    }
    PushDown(rt);
    int m = (l + r) >> ;
    if (L <= m&&MAX[rt << ] >= )update2(L, R, lson);
    if (R > m&&MAX[rt <<  | ] >= )update2(L, R, rson);
    tree[rt] = tree[rt << ] + tree[rt <<  | ];
    MAX[rt] = max(MAX[rt << ], MAX[rt <<  | ]);
}
int query(int L, int R, int l, int r, int rt)
{
    if (L <= l&&r <= R){
        return tree[rt];
    }
    int m = (l + r) >> , ans = ;
    if (L <= m)ans += query(L, R, lson);
    if (R > m)ans += query(L, R, rson);
    return ans;
}
void Print(int l, int r, int rt)
{
    if (l == r){
        cout << rt << " = " << MAX[rt] << endl;
        return;
    }
    cout << rt << " = " << MAX[rt] << endl;
    int m = (l + r) >> ;
    if (l <= m)Print(lson);
    if (r > m)Print(rson);
}
int main()
{
    std::ios::sync_with_stdio(false);
    int n, q;
    while (cin >> n >> q){
        for (int i = ; i <= n; i++)
            cin >> a[i];

        build(, n, );

        string flag; int l, r;
        for (int i = ; i < q; i++){
            cin >> flag >> l >> r;

            if (flag == "add"){
                update1(l, r, , n, );
                update2(l, r, , n, );
                //Print(1, n, 1);
            }
            else cout << query(l, r, , n, ) << endl;
        }
    }

    return ;
}