求教84分

mndogdied @ 2024-08-12 21:17:06

#include<bits/stdc++.h>
using namespace std;
int a,b,d;
int c;
struct C
{
    int num,st;
}r[1000002];

int Eggboss(int x)
{
    int l=0,rr=c+1;
    r[l].num=INT_MIN;
    r[rr].num=INT_MAX;
    while(l+1<rr)
    {
        int m=(l+rr)/2;
        if(r[m].num>x) rr=m;
        else if(r[m].num<x) l=m;
        else return r[m].st;
    }
    return -1;
}
signed main()
{
    r[1].num=-1;
    r[1].st=-1;
    cin>>a>>b;
    for(int i=1;i<=a;i++)
    {
        int s;
        cin>>s;
        if(s!=r[c].num)
        {
            c++;
            r[c].num=s;
            r[c].st=i;
        }
    } 
//  if(c==0) c=1;
    for(int i=1;i<=b;i++)
    {
        cin>>d;
        cout<<Eggboss(d)<<' ';
    }

    return 0;
}

by liruizhou_lihui @ 2024-08-12 21:22:22

while(l+1<rr)写成while(l<=rr)

rr=m写成rr=m-1

l=m写成 l=m+1

还有建议m写成mid这样你的程序更有可读性

by liruizhou_lihui @ 2024-08-12 21:24:31

求关

你可以拿我的对一下

//#include<bits/stdc++.h>
#include<iostream>
#include<math.h>
#include<cstring>
#include<string.h>
#include<algorithm>
#include<stdio.h>
using namespace std;
const int N=1e6 +1;
int a[N];
int n,x,m;
int main()
{
    //ios::sync_with_stdio(false),cin.tie(0);
    cin>>n>>m;
    for(int i=1;i<=n;i++)
    {
        cin>>a[i];
    }
    for(int i=0;i<m;i++)
    {
        cin>>x;
        int ans=-1;
        int l=1,r=n,mid;
        while(l<=r)
        {
            mid=(l+r)/2;
            if(x<a[mid])r=mid-1;
            else if(x>a[mid])l=mid+1;
            else
            {
                ans=mid;
                r=mid-1;
            }
        }
        cout<<ans<<' ';
    }

    return 0;
}