벡터를 함수에 전달하는 방법은 무엇입니까?

벡터를 함수에 전달하는 방법은 무엇입니까?

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벡터를 함수에 대한 인수로 보내려고하는데 어떻게 작동하는지 알아낼 수 없습니다. 여러 가지 방법을 시도했지만 모두 다른 오류 메시지를 표시합니다. 이 부분 만 작동하지 않기 때문에 코드의 일부만 포함합니다. (벡터 "random"은 0에서 200 사이의 임의의 값으로 채워지지만 정렬 됨)

코드 업데이트 :

#include <iostream>     
#include <ctime>        
#include <algorithm>    
#include <vector>       

using namespace std;

int binarySearch(int first, int last, int search4, vector<int>& random);

int main()
{
    vector<int> random(100);

    int search4, found;
    int first = 0;
    int last = 99;

    found = binarySearch(first, last, search4, random);

    system("pause");    
    return(0);      
}

int binarySearch(int first, int last, int search4, vector<int>& random)
{
    do
    {
        int mid = (first + last) / 2;  
        if (search4 > random[mid]) 
            first = mid + 1;  
        else if (search4 < random[mid]) 
            last = mid - 1; 
        else
            return mid;     
    } while (first <= last); 

    return -(first + 1);
}

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를 vector참조 또는 포인터로 전달할 것인지 여부에 따라 다릅니다 (값으로 전달하는 옵션을 분명히 바람직하지 않은 것으로 무시합니다).

참고로 :

int binarySearch(int first, int last, int search4, vector<int>& random);

vector<int> random(100);
// ...
found = binarySearch(first, last, search4, random);

포인터로서 :

int binarySearch(int first, int last, int search4, vector<int>* random);

vector<int> random(100);
// ...
found = binarySearch(first, last, search4, &random);

내부 binarySearch에서 해당 구성원 을 사용 .하거나 ->액세스 해야합니다 random.

현재 코드의 문제

1. binarySearch expects a vector<int>*, but you pass in a vector<int> (missing a & before random)
2. You do not dereference the pointer inside binarySearch before using it (for example, random[mid] should be (*random)[mid]
3. You are missing using namespace std; after the <include>s
4. The values you assign to first and last are wrong (should be 0 and 99 instead of random[0] and random[99]

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You'll have to pass the pointer to the vector, not the vector itself. Note the additional '&' here:

found = binarySearch(first, last, search4, &random);

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You're passing in a pointer *random but you're using it like a reference &random

The pointer (what you have) says "This is the address in memory that contains the address of random"

The reference says "This is the address of random"

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Anytime you're tempted to pass a collection (or pointer or reference to one) to a function, ask yourself whether you couldn't pass a couple of iterators instead. Chances are that by doing so, you'll make your function more versatile (e.g., make it trivial to work with data in another type of container when/if needed).

In this case, of course, there's not much point since the standard library already has perfectly good binary searching, but when/if you write something that's not already there, being able to use it on different types of containers is often quite handy.

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found = binarySearch(first, last, search4, &random);

Notice the &.

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You're using the argument as a reference but actually it's a pointer. Change vector<int>* to vector<int>&. And you should really set search4 to something before using it.

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If you use random instead of * random your code not give any error

참고URL : https://stackoverflow.com/questions/5333113/how-to-pass-a-vector-to-a-function