样例全过但是0分,求调

BlueTiger @ 2023-01-30 21:17:45

#include<iostream>
using namespace std;
int nums[100100100],n,m,ans;
int search(int target){
    int left=0;
    int right=n-1;  
    while(left<=right){  
        int middle=(left+right)/2;
        if(nums[middle]>target) right=middle-1;
        else if(nums[middle]<target) left=middle+1;
        else return middle;
    } 
    return -1;
}
int main(){ 
    cin>>n>>m;
    for(int i=1;i<=n;i++) cin>>nums[i];
    for(int i=1;i<=m;i++){
        int target;
        cin>>target;
        int ans=search(target);
        cout<<ans<<" ";
    } 
    cout<<endl;
    return 0; 
}

by gghack_Nythix @ 2023-01-30 21:20:10

可以用lower_bound

by BlueTiger @ 2023-01-30 21:22:08

@gghack_m3d

能手打我尽量不用lower_bound

by Accelessar @ 2023-01-30 21:25:49

left 设为 1，right 设为 n，因为你的数组是从 1 开始编号的。

by BlueTiger @ 2023-01-30 21:31:40

@AZN_0975 照错不误.

by Accelessar @ 2023-01-30 21:35:53

@BlueTiger 帮您改了一下

int search(int target){
    int left=1;
    int right=n;  
    while(left<=right){  
        int middle=(left+right)/2;
        if(nums[middle]>=target) right=middle-1;
        else  left=middle+1;
    } 
    return nums[left]==target?left:-1;
}

by gghack_Nythix @ 2023-01-30 21:37:29

@BlueTiger 过了

#include<iostream>
using namespace std;
int nums[100100100],n,m,ans;
int search(int target){
    int left=1,ans = 0;
    int right=n;  
    while(left<=right){  
        int middle=(left+right)/2;
        if(nums[middle]>=target) //第一个错的{right=middle-1;ans = middle;//记录一下ans，有可能是答案}
        else left = middle + 1;
    } 
    if(nums[ans] == target){//验证
        return ans;
    }
    return -1;
}
int main(){ 
    cin>>n>>m;
    for(int i=1;i<=n;i++) cin>>nums[i];
    for(int i=1;i<=m;i++){
        int target;
        cin>>target;
        int ans=search(target);
        cout<<ans<<" ";
    } 
    cout<<endl;
    return 0; 
}

by BlueTiger @ 2023-02-01 20:46:33

@gghack_m3d @AZN_0975 谢谢大佬,过了

by Do_www @ 2023-02-01 21:14:17

@AZN_0975 佬，这题数组从0开始为啥过不去啊

by Accelessar @ 2023-02-01 21:25:22

@wry_123 最后输出时要将 l 加 1，因为题目问的编号是从 1 开始的编号。