归并排序

#include<iostream>
#include<stdio.h>
#define maxn 100
using namespace std;

void merge(int arr[],low,mid,high){
    int i,j,k;
    int n1=mid-low+1;
    int n2=high-mid;
    int L[n1],R[n2];
    for(i=0;i<n1;i++){
        L[i]=arr[low+i];
    }
    for(j=0;j<n2;j++){
        R[j]=arr[mid+1+j];
    }
    i=0;
    j=0;
    k=low;
    while(i<n1&&j<n2){
        if(L[i]<=R[j]){
            arr[k]=L[i];
            k++;
            i++;
        }else{
            arr[k]=R[j];
            k++;
            j++;
        }
    }
    while(i<n1){
        arr[k]=L[i];
        k++;
        i++;
    }
    while(j<n2){
        arr[k]=R[j];
        k++;
        j++;
    }
}

void mergeSort(int arr[],int low,int high){
    if(low<high){
        int mid=(low+high)/2;
        mergeSort(arr,low,mid);
        mergeSort(arr,mid+1,high);
        merge(arr,low,mid,high);
    }
}
int main(){
    int arr[maxn];
    cout<<"请输入一组数据：";
    int i; //记载输入了多少个数
    for(i=0;;i++){
        cin>>arr[i];
        if(getchar()=='\n'){
            break;
        }
    }
    mergeSort(arr,0,i);
    for(int j=0;j<=i;j++){
        cout<<arr[j]<<" ";
    }
    return 0;
}