除了第2、3个AC，其他全MLE，求大佬看看，JAVA代码

P2249 【深基13.例1】查找

_Satoru_ @ 2024-05-29 23:02:39

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        int n = scan.nextInt();
        int q = scan.nextInt();
        int[] arr = new int[n];
        int[] k = new int[q];   
        for(int i = 0;i<n;i++) {
            arr[i]=scan.nextInt();
        }
        for(int i=0;i<q;i++) {
            k[i]=scan.nextInt();
        }

        for(int i=0;i<q;i++) {
            int l = -1;
            int r = n;
            int mid = 0;
            while(l+1!=r) {
                mid=(l+r)/2;
                if(arr[mid]<k[i]) {
                    l=mid;
                }else {
                    r=mid;
                }
            }
            if(r>=n||arr[r]!=k[i]) {
                System.out.print(-1+" ");
                continue;
            }
            System.out.print(r+1+" ");
        }
    }
}

by chrispang @ 2024-05-29 23:07:47

我也才刚写完这道题

#include <iostream>
using namespace std;

int n, m, a[1000010];
int erfen(int x) {
    int l = 1, r = n;
    while (l < r) { //最后l和r会相等
        int mid = l + (r - l) / 2;
        if (a[mid] >= x) r = mid;
        else l = mid + 1;
    }
    if (a[l] == x) return l;
    else return -1;
}

int main() {
    cin >> n >> m;
    for (int i = 1; i <= n; i++)
        cin >> a[i];
    for (int i = 1; i <= m; i++) {
        int q; cin >> q;
        cout << erfen(q) << " ";
    }
    return 0;
}