D. Berserk Monsters

合集 - codeforces(57)

1.C. Insert and Equalize2023-12-062.C. Removal of Unattractive Pairs2023-12-063.D. Jumping Through Segments2023-12-084.E. Good Triples2023-12-085.F. Shift and Reverse2023-12-086.D. Yet Another Monster Fight2023-12-117.A. Constructive Problems2023-12-188.C. Game with Multiset2023-12-199.A. Rating Increase2023-12-1910.B. Swap and Delete2023-12-1911.A. Problemsolving Log2023-12-2012.B. Preparing for the Contest2023-12-2013.C. Quests2023-12-2014.D. Three Activities2023-12-2015.E2. Game with Marbles (Hard Version)2023-12-2016.cf刷题有感2023-12-2017.A. Anonymous Informant2023-12-2118.A. Forked!2023-12-2319.B. Make Almost Equal With Mod2023-12-2720.C. Heavy Intervals2023-12-2721.D. Split Plus K2023-12-2822.A. 20232023-12-3123.B. Two Divisors2023-12-3124.C. Training Before the Olympiad2023-12-3125.D. Mathematical Problem2024-01-0226.F. Greetings2024-01-0227.C. Partitioning the Array2024-01-1528.G. Bicycles2024-01-1629.E. Eat the Chip2024-01-1730.G. Lights2024-01-1731.D. Array Repetition2024-01-17

32.D. Berserk Monsters2024-01-22

33.E. Increasing Subsequences2024-01-2334.D. Very Different Array2024-01-2435.G. Mischievous Shooter2024-01-2536.B. Plus-Minus Split2024-01-2737.B. A Balanced Problemset2024-01-2838.C. Did We Get Everything Covered2024-01-2839.D. Find the Different Ones!2024-02-0840.C. Grouping Increases2024-02-1041.D. Good Trip2024-02-1242.C. Physical Education Lesson2024-02-1243.E. Final Countdown2024-02-1844.D. Divisible Pairs2024-02-1945.G. Vlad and Trouble at MIT2024-02-2046.A. Brick Wall2024-02-2847.B. Minimize Inversions2024-02-2848.C. XOR-distance2024-02-2849.A. Moving Chips2024-02-2850.B. Monsters Attack!2024-02-2851.C. Find B2024-02-2852.D. Slimes2024-02-2853.C. Turtle Fingers: Count the Values of k2024-02-2854.D. Turtle Tenacity: Continual Mods2024-02-2855.D. Vlad and Division2024-02-2856.C. LR-remainders2024-02-2857.D. Lonely Mountain Dungeons2024-03-12

收起

原题链接

题解

1.最笨的想法，链表，每次在还没被杀死的怪物里遍历一遍，如果被杀死了就从链表中删除这个节点
但是TLE on #7

2.进阶想法，仍然是链表，我们想，如果有些怪物永远都不会被杀死，那我们就没必要遍历它。所以我们从可能被杀死的怪物中遍历
如果一个怪物这个回合被杀死，但是在上个回合中没有被杀死，说明它的两侧怪物发生了变动，说明了上个回合它的两侧怪物被杀死了
所以优化方法如下：一开始把所有的怪物都放进第一回合可能被杀死的集合中，然后遍历集合，如果有怪物被杀死，其两侧的怪物放入下一回合可能被杀的集合中

code

#include<bits/stdc++.h>
using namespace std;
int a[300005]={0},b[300005]={0};
struct
{
    int l,r,a,b;
}gw[300005];
int main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    gw[0].a=0,gw[0].b=0;
    int t;
    cin>>t;
    while(t--)
    {
        int n;
        cin>>n;
        for(int i=1;i<=n;i++)cin>>gw[i].a;
        for(int i=1;i<=n;i++)cin>>gw[i].b;

        set<int> maybe;//代表可能被删的怪物
        for(int i=1;i<=n;i++)
        {
            gw[i].l=i-1;
            gw[i].r=i+1;
            maybe.insert(i);
        }

        gw[n].r=0;
        int out[300005]={1};//初始化0已被删
        for(int i=1;i<=n;i++)
        {
            vector<int> dellist;
            for(int j : maybe)
            {
                int L=gw[j].l,R=gw[j].r;
                if(gw[j].b<gw[L].a+gw[R].a&&!out[j]) dellist.push_back(j);//如果不判断out，被删掉的元素还有可能继续被删
                //先放再删是因为攻击是同时进行的，还需要当前怪物的配合
            }
            maybe.clear();
            cout<<dellist.size()<<" ";
            for(int j=0;j<dellist.size();j++)
            {
                int now=dellist[j];
                out[now]=1;//代表已被删
                int L=gw[now].l,R=gw[now].r;
                gw[L].r=R;
                gw[R].l=L;
                maybe.insert(L);
                maybe.insert(R);
            }
        }
        cout<<endl;
    }
    return 0;
}