二分查找法(C语言实现)

Dear 丶 2023-02-14 10:39 22阅读 0赞

#include <stdio.h>
    #include <stdlib.h>
    
    int BinarySearch(int arr[],int n,int key)
    { 
        int low,hight,middle;
        low = 0;
        hight = n - 1;
        while(hight >= low){ 
            middle = (low + hight) / 2;
            if(key == arr[middle]){ 
                return (middle + 1);
            }
            if(key > arr[middle]){ 
                low = middle + 1;
            }
            if(key < arr[middle]){ 
                hight = middle - 1;
            }
        }
        return -1;
    }
    int main()
    { 
        int n,i,key,l,num;
        printf("请输入数据的个数:");
        scanf("%d",&n);
        printf("\n");
        int arr[n];
        printf("请按从小到大的顺序输入您的数据(空格隔开):");
        for(i = 0;i < n;i ++){ 
            scanf("%d",&arr[i]);
        }
        printf("\n");
        while(1){ 
            printf("请在下面输入您想要的操作\n\n");
            printf("1.查数!\n\n");
            printf("2.退出!\n\n");
            printf("请输入:");
            scanf("%d",&num);
            printf("\n");
            switch(num){ 
                case 1:
                    { 
                    printf("请输入您想查找的数:");
                    scanf("%d",&key);
                    printf("\n");
                    l = BinarySearch(arr,n,key);
                    if(-1 == l){ 
                        printf("没找到哦!");
                        printf("\n\n");
                    }else{ 
                        printf("%d的值在第%d位置上!",key,l);
                        printf("\n\n");
                    }
                    break;
                }
                case 2:
                    { 
                        return;
                }
            }
        }
    }

比较简单,小伙伴有什么不懂可以在下边留言或私信我，  
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