数据结构排序算法--归并排序

归并排序

---

#include <iostream>
#include <cstdio>

using namespace std;


void combineNum(int left,int middle,int right){
    int i = left;
    int j = middle+1;
    int k = left;
    while(i <= middle && j <= right){
        if(arr[i] <= arr[j]){
            temp[k++] = arr[i++];
        }else{
            temp[k++] = arr[j++];
        }
    }

    while (i <= middle){
        temp[k++] = arr[i++];
    }
    while (j <= right){
        temp[k++] = arr[j++];
    }

    for (int l = left; l <= right; ++l) {
        arr[l] = temp[l];
    }
}

void mergeSort(int left,int right){
    if(left < right){
        int middle = left + (right - left)/2;
        mergeSort(left,middle);
        mergeSort(middle+1,right);
        combineNum(left,middle,right);
    }
}

/**
 * 归并排序的算法实现
 */
 int main(){
     int n;
     while(scanf("%d",&n)!= EOF){
         for (int i = 0; i < n; ++i) {
             scanf("%d",&arr[i]);
         }
         mergeSort(0,n-1);

         for (int j = 0; j < n; ++j) {
             printf("%d ",arr[j]);
         }
         printf("\n");
     }
 }