题目:把一个数组最开始的若干个元素搬到数组末尾,即数组的旋转;
例如:{3,4,5,1,2}是{1,2,3,4,5}的一个旋转,输出该数组的最小值1
代码如下:
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
//顺序查找最小值
int Order(int *numbers,int index1,int index2)
{
int result=numbers[index1];
for(int i=index1+1;i<=index2;++i)
{
if(result>numbers[i])
{
result=numbers[i];
}
}
return result;
}
int Min(int *numbers,int length)
{
if(numbers==nullptr||length<=0) //判断若数组为空,或长度若小于0,则不合法
{
printf("error");
}
int index1=0; //初始化index1为0号下标,即第一个数组
int index2=length-1; //初始化index2为最后一个数组的下标
int indexMid=index1; //
while(numbers[index1]>=numbers[index2])
{
if(index2-index1==1)
{
indexMid=index2;
break;
}
indexMid=(index1+index2)/2; //让indexMid 指向数组中间的值
//若下标index1 index2 indexMid 的值都相等 则只能顺序寻找
if(numbers[index1]==numbers[index2]&&numbers[indexMid]==numbers[index1])
{
return Order(numbers,index1,index2);
}
//若中间值位于前面的递增数组,则在后面一半找最小值
if(numbers[indexMid]>=numbers[index1])
index1=indexMid;
//若中间值位于后面的递增数组,则在前面一半找最小值
else if(numbers[indexMid]<=numbers[index2])
index2=indexMid;
}
return numbers[indexMid];
}
int main()
{
int numbers1[5]={2,3,4,67,1};
int numbers2[5]={1,4,5,6,7};
int numbers3[5]={1,2,3,2,1};
printf("%d\n",Min(numbers1,5));
printf("%d\n",Min(numbers1,5));
printf("%d\n",Min(numbers1,5));
return 0;
}
运行结果: