救救孩子吧，这二分写得有问题吗？

PURE_LOVE @ 2024-03-19 14:17:43

#include<bits/stdc++.h>
using namespace std;
int n = 0, m = 0; 
int mark = 0;
int chazhao(int a,vector<int>arr,int left,int right)
{
    int mid = (left + right) / 2;
    if (left == right)
    {
        if (arr[left]==a)
            return left+1;
        else
            return -1;
    }
    else if(arr[mid] >= a)
    {
        return chazhao(a, arr, left, mid);
    }
    else
    {
        return chazhao(a, arr, mid+1, right);
    }
}
int main()
{
    scanf("%d%d", &n, &m);
    vector<int>arr(n);
    vector<int>brr(m);
    for (int i = 0; i < n; i++)
    {
        scanf("%d", &arr[i]);
    }
    for (int i = 0; i < m; i++)
    {
        scanf("%d", &brr[i]);
        int temp=chazhao(brr[i], arr, 0, n - 1);
        printf("%d ", temp);
    }
}```c

by tanlihan @ 2024-03-19 14:37:51

@PURE_LOVE 你把vector数组定义成全局它就不会超时了。

by PURE_LOVE @ 2024-03-19 14:52:50

@tanlihan 感谢佬，刚学着用vector还不是很明白，谢谢佬

by PURE_LOVE @ 2024-03-19 15:06:33

@tanlihan 佬 我改完之后re了，是为什么啊

#include<bits/stdc++.h>
using namespace std;
int n = 0, m = 0; 
vector<int>arr(1000001);
vector<int>brr(10001);
int mark = 0;
int chazhao(int a,int left,int right)
{
    int mid = (left + right) / 2;
    if (left>= right)
    {
        if (arr[left]==a)
            return left+1;
        else
            return -1;
    }
    else if(arr[mid] >= a)
    {
        return chazhao(a,  left, mid);
    }
    else
    {
        return chazhao(a, mid+1, right);
    }
}
int main()
{
    scanf("%d%d", &n, &m);
    for (int i = 0; i < n; i++)
    {
        scanf("%d", &arr[i]);
    }
    for (int i = 0; i < m; i++)
    {
        scanf("%d", &brr[i]);
        int temp=chazhao(brr[i],  0, n - 1);
        printf("%d ", temp);
    }
}```c

by tanlihan @ 2024-03-19 15:21:49

@PURE_LOVE 1 \le m \le 10 ^ 5，你开的是 10^4

by PURE_LOVE @ 2024-03-19 15:55:38

@tanlihan 爱了爱了