ACM-ICPC 2018 南京赛区网络预赛 G. Lpl and Energy-saving Lamps (弱线段树)

Posted 2021-01-06 xiuwenli

线段树节点维护区间最小值,查找时优先从左侧的区间寻找.
每一次循环都在树中不停寻找第一个小于等于当前持有数的值,然后抹去,直到找不到为止.

#include<cstdio>
#include<iostream>
#include<algorithm>
#include<cstring>
#define lson rt<<1
#define rson rt<<1|1
#define Lson l,m,lson
#define Rson m+1,r,rson
using namespace std;
typedef long long LL;
const int INF = 0x3f3f3f3f;
const int maxn=1e5+5;
int val[maxn];
struct Node{
    int num;
}tree[maxn<<2];
int n;
void pushup(int rt)
{
    tree[rt].num = min(tree[lson].num,tree[rson].num);
}

void build(int l=1,int r=n,int rt=1)
{
    if(l==r){
        tree[rt].num = val[l];
        return ;
    }
    int m = (l+r)>>1;
    build(Lson);
    build(Rson);
    pushup(rt);
}

bool flag;
int query(int val,int l=1,int r=n,int rt=1)
{
    int res=-1,m = (l+r)>>1;
    if(tree[rt].num<=val){
        if(l==r){
            int tmp = tree[rt].num;
            tree[rt].num = INF;
            return  tmp;
        }
        res = query(val,Lson);
        if(res!=-1) {
            pushup(rt);
            return res;
        }
        res = query(val,Rson);
        if(res!=-1){
            pushup(rt);
            return res;
        }
    }
    return -1;
}

int ans1[maxn];
int ans2[maxn];
int main()
{
    #ifndef ONLINE_JUDGE
        freopen("in.txt","r",stdin);
        freopen("out.txt","w",stdout);
    #endif
    int m,q;
    while(scanf("%d %d",&n,&m)==2){
        for(int i=1;i<=n;++i){
            scanf("%d",&val[i]);
        }
        build();
        flag = false;
        int sum = 0,tot=0;
        for(int i=1;i<=100000;++i){
            //cout<<tree[1].num<<endl;
            if(tree[1].num ==INF) flag = true;
            if(!flag) {
                sum += m;
                int tmp = query(sum);
                while(tmp!=-1){
                    sum-=tmp;
                    tot++;
                    tmp = query(sum);
                }
            }
            ans1[i] = tot;
            ans2[i] = sum;
        }
        int id;
        scanf("%d",&q);
        for(int i=1;i<=q;++i){
            scanf("%d",&id);
            printf("%d %d
",ans1[id],ans2[id]);
        }
    }
    return 0;
}