selection sort實踐

void select(int arr[10])
{
    int i,j,min,idx,tp;
    for(i=0;i<10-1;i++)
    {
        min=INT_MAX;
        idx = -1;
        for(j=i;j<10;j++)
        {
            if(min>=arr[j])
            {
                min = arr[j];
                idx =j;
            }
        }
        tp = arr[i];
        arr[i] = arr[idx];
        arr[idx] = tp;
    }
}

int main()
{
    int arr[10]={5,3,2,2,0,1,3,4,6,8};
    int i;
    select(arr);
    for(i=0;i<10;i++)
        printf("%d ",arr[i]);
    printf("\n");
    return 0;
}

C 常數指標筆記

pointer to variable can not be modified, but pointer can be modified.

int a=1;
int b=3;
int const *p=&a;
const int *p2=&a;
*p=2; // failed
*p2=2; // failed
p=&b; // success
p2=&b; //success

pointer to variable can be modified, but pointer can not be modified.

int a=1;
int b=3;
int *const p=&a;
*p=2; // success
p=&b; // failed

pointer to variable can not be modified, and pointer can not be modified.

int a=1;
int b=3;
const int *const p=&a;
*p=2; // failed
p=&b; // failed