鏈接：https://ac.nowcoder.com/acm/contest/371/B
來源：牛客網

void generate_array(int n,int seed)
{
    unsigned x = seed;
    for (int i=1;i<=n;++i)
    {
        x ^= x << 13;
        x ^= x >> 17;
        x ^= x << 5;
        val[i]=x%100;
    }
}

void generate_ask(int n,int m,int seedx,int seedy)
{
    unsigned x=seedx,y=seedy;
    for (int i=1;i<=m;++i)
    {
        x ^= x << 13;
        x ^= x >> 17;
        x ^= x << 5;
        y ^= y << 13;
        y ^= y >> 17;
        y ^= y << 5;
        L=(x^lastans)%n+1,R=(y^lastans)%n+1;
        if (L>R)swap(L,R);
        //解決詢問
    }
}

輸入描述:

第1行2個整數n,m，分別表示序列長度和詢問次數

第2行3個整數seed,seedx,seedy，意義如題所示

輸出描述:

一行一個整數，表示所有詢問的答案的異或和

輸入

10 5
3 5 7

輸出

2

思路:裸的ST

#include <cstdio>
#include <map>
#include <iostream>
#include<cstring>
#include
 
<bits/stdc++.h>
#define ll long long int
#define M 6
using namespace std;
inline ll gcd(ll a,ll b){return b?gcd(b,a%b):a;}
inline ll lcm(ll a,ll b){return a/gcd(a,b)*b;}
int moth[13]={0,31,28,31,30,31,30,31,31,30,31,30,31};
int dir[4][2]={1,0 ,0,1 ,-1,0 ,0,-1};
int dirs[8][2]={1,0 ,0,1 ,-1,0 ,0,-1, -1,-1 ,-1,1 ,1,-1 ,1,1};
const int inf=0x3f3f3f3f;
const ll mod=1e9+7;
int val[100007];
int f[100007][20];
int L,R,lastans,ans;
void generate_array(int n,int seed)
{
    unsigned x = seed;
    for (int i=1;i<=n;++i)
    {
        x ^= x << 13;
        x ^= x >> 17;
        x ^= x << 5;
        val[i]=x%100;
    }
}
int maxn(int i,int j){
    if(val[i]>val[j]) return i;
    else if(val[i]<val[j]) return j;
    else return i>j?j:i;
}
void preST(int len){
    for(int i=1;i<=len;i++) f[i][0]=i;
    int k=log(len)/log(2)+1;
    for(int j=1;j<k;j++)
        for(int i=1;i<=(len-(1<<j)+1);i++)
            f[i][j]=maxn(f[i][j-1],f[i+(1<<(j-1))][j-1]);
}
int queryST(int l,int r){
    int k=log(r-l+1)/log(2);
    return maxn(f[l][k],f[r-(1<<k)+1][k]);
}
void generate_ask(int n,int m,int seedx,int seedy)
{
    unsigned x=seedx,y=seedy;
    for (int i=1;i<=m;++i)
    {
        x ^= x << 13;
        x ^= x >> 17;
        x ^= x << 5;
        y ^= y << 13;
        y ^= y >> 17;
        y ^= y << 5;
        L=(x^lastans)%n+1,R=(y^lastans)%n+1;
        if (L>R)swap(L,R);
       // cout<<L<<" "<<R<<endl;
        lastans=queryST(L,R);
       // cout<<lastans<<endl;
        ans^=lastans;
    }
    cout<<ans<<endl;
}
int main(){
    ios::sync_with_stdio(false);
    int seed,seedx,seedy;
    int n,m;
    while(cin>>n>>m){
        cin>>seed>>seedx>>seedy;
        generate_array(n,seed);
        lastans=0;
        int tt=m;
        ans=0;
        preST(n);
        generate_ask(n,tt,seedx,seedy);
    }
}

牛客OI周賽7-提高組 B小睿睿的詢問(ST打表)