C++中的二进制搜索排序和索引

Binary Search sorting and indexing in C++

本文关键字：排序 索引 搜索 二进制 C++      更新时间：2023-10-16

问题：给定一个数组(ArrayInts(，计算所有偶数整数和奇数整数的和，并使用二进制搜索在数组中搜索所有奇数整数和的目标值。如果在数组中找到目标值，则显示找到目标值的数组索引，否则显示未找到目标

我没有得到正确的答案。我不相信我想被读取的数组正在被读取。当我编译时，我得到数组是{6487456}，偶数之和是678，赔率是549，二进制搜索找不到目标。这是我现在的代码：

#include <stdio.h> 
#include <stdlib.h>
#include <math.h>

double ArrayInts[]={54,152,99,-8,3,19,-11,260,27,-4,10,12,15,58,480,60};
int Bin_Search(double ArrayInts[],int low, int high, double target);
int main(void)
{
int i,j,n=16,sum_even,sum_odd, index,len;
double ArrayInts[16]={54,152,99,-8,3,19,-11,260,27,-4,10,12,15,58,480,60}, target;
//Implemeting Bubble sort
for(i=0;i<n-1;i++)
    for(j=0;j<n-1;j++)
    {
        if (ArrayInts[j]>ArrayInts[j+1])
        {
            len=ArrayInts[j];
            ArrayInts[j]=ArrayInts[j+1];
            ArrayInts[j+1]=len;
        }
    }
//Function call to add even and odd numbers from array
for(i=0;i<16;i++)
{
    if(i%2==0)
    sum_even+=ArrayInts[i];
    else
    sum_odd+=ArrayInts[i];
}
printf("The array is {%d}n",ArrayInts);
printf("The sum of all even numbers in the array is: %dn",sum_even);
printf("The sum of all odd numbers in the array is: %dn",sum_odd);
//Function call to search for target value
index = Bin_Search(ArrayInts,0,15,target); 
if(index != -1)
printf("Target found at index %dn", index);
else
printf("Target was not foundn");
system("pause");
return (0);
}
int Bin_Search(double ArrayInts[],int low, int high, double target)
{
int mid;
if (low>high)
    return -1;
mid=(low+high)/2;
if(ArrayInts[mid]==target)
    return(mid);
else if (ArrayInts[mid]<target)
    return Bin_Search(ArrayInts, mid+1, high, target);
else
    return Bin_Search(ArrayInts, low, mid-1, target);     
}

sum_even未初始化。

sum_odd未初始化。

target未初始化。

这些变量均未初始化。因此，这会导致未定义的行为。

假设这是所谓的c++，请使用std::sort对数组进行排序，而不是编写自己的排序。如果这真的是C，请使用qsort(3(。

对于范围/V3，它将是：

std::vector<int> v = {54,152,99,-8,3,19,-11,260,27,-4,10,12,15,58,480,60, 480-163};
auto is_even = [](int i) {return i % 2 == 0;};
auto is_odd = [](int i) {return i % 2 == 1;};
const auto even_sum = ranges::v3::accumulate(v | ranges::v3::view::filter(is_even), 0);
const auto odd_sum = ranges::v3::accumulate(v | ranges::v3::view::filter(is_odd), 0);
ranges::v3::sort(v);
const auto target = 27;
auto found = ranges::v3::binary_search(v, target);
std::cout << "The sum of all even numbers in the array is:" << even_sum << std::endl;
std::cout << "The sum of all odd numbers in the array is:" << odd_sum << std::endl;
std::cout << target << (found ? " Found" : " Not found") << std::endl;

演示

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