[SCOI2007]降雨量

ST表,再大力讨论一下(因为lower_bound和upper_bound,WA了一次

# include <bits/stdc++.h>
# define RG register
# define IL inline
# define Fill(a, b) memset(a, b, sizeof(a))
using namespace std;
typedef long long ll;
const int _(5e4 + 10);

IL ll Read(){
    char c = '%'; ll x = 0, z = 1;
    for(; c > '9' || c < '0'; c = getchar()) if(c == '-') z = -1;
    for(; c >= '0' && c <= '9'; c = getchar()) x = x * 10 + c - '0';
    return x * z;
}

int n, val[_], r[_], m, st[_][20], lg[_];

IL int Query(RG int x, RG int y){
    if(x > y) return -1e9;
    RG int l = lg[y - x + 1];
    return max(st[x][l], st[y - (1 << l) + 1][l]);
}

IL int Judge(RG int x, RG int y){
    RG int fx = lower_bound(val + 1, val + n + 1, x) - val, fy = lower_bound(val + 1, val + n + 1, y) - val;
    RG int bx = val[fx] == x, by = val[fy] == y, q;
    if(bx){
        if(by){
            q = Query(fx + 1, fy - 1);
            if(r[fx] < r[fy]) return 0;
            if(q < r[fy]){
                if(fy - fx == y - x) return 2;
                return 1;
            }
            return 0;
        }
        else{
            q = Query(fx + 1, fy - 1);
            if(q < r[fx]) return 1;
            return 0;
        }
    }
    else{
        if(by){
            q = Query(fx, fy - 1);
            if(q < r[fy]) return 1;
            return 0;
        }
        else return 1;
    }
}

int main(RG int argc, RG char *argv[]){
    n = Read();
    for(RG int i = 2; i <= n; i++) lg[i] = lg[i >> 1] + 1;
    for(RG int i = 1; i <= n; i++) val[i] = Read(), r[i] = Read(), st[i][0] = r[i];
    for(RG int j = 1; j <= lg[n]; j++)
        for(RG int i = 1; i + (1 << j) - 1 <= n; i++)
            st[i][j] = max(st[i][j - 1], st[i + (1 << (j - 1))][j - 1]);
    m = Read();
    while(m--){
        RG int y = Read(), x = Read(), flg = Judge(y, x);
        if(flg == 0) puts("false");
        else if(flg == 1) puts("maybe");
        else puts("true");
    }
    return 0;
}
原文地址:https://www.cnblogs.com/cjoieryl/p/8206342.html