（排序回顾）归并排序

Posted 2020-10-08 年糕君の勉强笔记

#include <iostream>
using namespace std;
int a[10];
int temp[10];

void mergeArray(int left,int right,int mid){
    int i = left;
    int j = mid + 1;
    int k = 0;

    while( i <= mid && j <= right) {
        if(a[i] < a[j]){
            temp[k++] = a[i++];
        } else {
            temp[k++] = a[j++];
        }
    }

    while( i<=mid ){
        temp[k++] = a[i++];
    }

    while( j<=right ){
        temp[k++] = a[j++];
    }

    k = 0;
    while(left <= right ){
        a[left++] = temp[k++];
    }
}

void mergeSort(int left,int right){
    if(left < right){
        int mid = (left+right)/2;
        mergeSort(left,mid);
        mergeSort(mid+1,right);
        mergeArray(left,right,mid);
    }
}

int main()
{
    int n;
    cin>>n;

    for(int i=0;i<n;i++){
        cin>>a[i];
    }

    mergeSort(0,n-1);
    for(int i=0;i<n;i++){
        cout<<a[i]<<endl;
    }
    return 0;
}