排序汇总

Posted 2020-12-24 zoulingjin

1.选择排序

for(i=0;i<n-1;i++){//n-1趟
        int k=i;//令第一个数为最小值 
        for(j=i+1;j<n;j++){
            if(a[k]>a[j]){
                t = a[k];
                a[k] = a[j];
                a[j] = t;
            }
        }
    }

2.冒泡排序

for(i=0;i<n-1;i++){//n-1趟冒泡 
        for(j=0;j<n-i-1;j++){
            if(a[j]>a[j+1]){
                t = a[j];
                a[j] = a[j+1];
                a[j+1] = t;
            }
        }
    }

3.快速排序(排序不稳定)

void quick_sort(int a[],int low,int high){
    int pivot = a[low];
    int i = low+1;
    int j = high;int temp;
    while(i<j){
        while((i<j)&&pivot<=a[j]){
            --j;
        }
        while((i<j)&&pivot>=a[i]){
            ++i;
        }
        if(i<j){
            temp = a[i];
            a[i] = a[j];
            a[j] = temp;
        }
    }
    if(a[low]>a[j]){
        temp = a[low];
        a[low] = a[j];
        a[j] = temp;
    }
    if(i-low>1)
    quick_sort(a,low,i-1);
    
    if(high-j>1)
    quick_sort(a,j+1,high);
}