二分 选择回顾

#include <stdio.h>

int main() {
    int arr[5] = {1,3,34,43,22};
    int tmp,idx;
    for(int i=0;i<4;i++) {
        
        idx = i;
        
        for(int j=i+1;j<5;j++) {
            if (arr[idx] > arr[j]) {
                idx = j;
            }
        }
        
        if (idx !=i) {
            tmp = arr[idx];
            arr[idx] = arr[i];
            arr[i] = tmp;
        }
    }
    for(int i= 0;i<5;i++) {
        
        printf("%d\n",arr[i]);
    }
    return 0;
}


void demo1 () {
    int arr[5] = {1,3,34,43,22};
    
    int tmp;
    for(int i=0;i<4;i++) {
        for(int j=i+1;j<5;j++) {
            
            if (arr[i]>arr[j]) {
                tmp = arr[i];
                arr[i] = arr[j];
                arr[j] = tmp;
            }
        }
        
    }
    for(int i= 0;i<5;i++) {
        
        printf("%d\n",arr[i]);
    }
}

void demo2() {

    int data = 14;
    int arr[5] = {13,25,233,22332,333333};
    int left = 0,right = 5,mid,idx;
    
    while (left <= right) {
        mid = (left+right)/2;
        if (arr[mid] == data){
            idx = mid;
            break;
        }
        if (arr[mid] > data) right = mid - 1;
        if (arr[mid] < data) left = mid + 1;
    }
    
    printf("%d",idx);

}