归并排序是一种独立的排序思想,其排序准则就是“先行拆分,小组排序;之后归并,再行排序”。代码如下:
public static void merge(int[]arr,int low,int m,int high){
int[]temp=new int[high-low+1];
int i=low;
int j=m+1;
int index=0;
while(i<=m && j<=high){
if(arr[i]<=arr[j]){
temp[index]=arr[i];
i++;
}else{
temp[index]=arr[j];
j++;
}
index++;
}
while(j<=high){
temp[index]=arr[j];
j++;
index++;
}
while(i<=m){
temp[index]=arr[i];
i++;
index++;
}
for(int k=0;k<temp.length;k++){
arr[k+low]=temp[k];
}
}
public static void mergeSort(int[]arr,int low,int high){
int middle=(high+low)/2;
if(low<high){
mergeSort(arr,low,middle);
mergeSort(arr,middle+1,high);
merge(arr,low,middle,high);
}
}