排序然后搜索(向量c ++)

问题描述 投票:0回答:1

我已经尝试过使用向量而不是固定内存数组单独进行搜索,并且效果很好。但是现在当我尝试首先对向量进行排序以使其能够在二元搜索中工作时,在用户输入向量列表后,程序将停止这是代码

#include <iostream>
#include <vector>
using namespace std;
void BubbleSort(vector<int>list){
    int temp;
    for (int i=0;i<list.size();i++){
        for (int j=1;j<list.size();j++){
            if(list[i]>list[j]){
                list[i]=temp;
                list[j]=list[i];
                temp=list[j];
            }
        }
    }
}
int Binary_search(vector<int>list,int target){
    int maximum=(list.size())-1;
    int minimum = 0;
    int mean;
    while (maximum>minimum){
        mean = (maximum+minimum)/2;
        if (list[mean] == target){
            cout << "The number you're looking for is found! \n";
            return mean;
        }
        else if(list[mean] > target){
            maximum = mean;
        }
        else{
            minimum = mean;
        }
    }
    return -1;
}
int main()
{
    unsigned int k;
    int x,a,target;
    vector<int>list;
    cout << "Enter the amount of numbers you want to enlist \n";
    cin >> k;
    while((list.size()< k) && (cin >> x)){
        list.push_back(a);
    }
    BubbleSort(list);
    cout << "Enter the target that you want to search for \n";
    cin >> target;
    int result = Binary_search(list,target);
    if(result == -1){
        cout << "Your result is not found ";
    }
    else{
        cout << "Your result is found at the index: " << result;
    }
    return 0;
}

我希望程序进行排序(但不要打印出排序的向量,只是从后面进行排序,然后在搜索后在最后显示结果)问题肯定在排序部分,但是我不知道在它之前使用Bubble Sort是否可以,有人可以指出我正确的排序方式然后搜索吗?

c++ sorting search vector
1个回答
0
投票

@@ Oliver_Queen您的代码中有一些麻烦,但是如果您遵循@ 1201ProgramAlarm和@Blastfurnace的注释,则可以解决部分问题,但在Binary_search()函数中,应将mean-1mean+1用于maximumminimum并检查极端条件是否为真,这是固定的代码:

void BubbleSort(vector<int> &list){
    int temp;
    for (int i=0;i<list.size();i++){
        for (int j=i+1;j<list.size();j++){
            if(list[i]>list[j]){
                temp=list[i];
                list[i]=list[j];
                list[j]=temp;
            }
        }
    }
}

以及在函数Binary_search()中:

int Binary_search(vector<int>list,int target){
    int maximum=(list.size())-1;
    int minimum = 0;
    int mean;
    while (maximum>minimum){
        mean = (maximum+minimum)/2;
        if (list[mean] == target){
            cout << "The number you're looking for is found! \n";
            return mean;
        }
        else if(list[mean] > target){
            maximum = mean-1;
        }
        else{
            minimum = mean+1;
        }
    }
    if (list[minimum] == target) return minimum;
    return -1;
}

但是我的建议是您使用算法库的std::sort()来执行std::sort()中的排序,其中O(N*log(N))是要排序的项目数,然后使用N检查它是否属于或std::binary_search找到不小于给定值的第一项。

std::binary_search
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