二分法查找需要先排序
public class Erfangfa {
//二方法查找是折半查找,优点是比较次数少 确定是待查表示有序的,
public static void main(String[] args) {
int [] num={90,35,40,53,50,18,23,80};
Arrays.sort(num);//排序
System.out.println(binarySearch(num, 30));
}
public static int binarySearch(int [] nums,int key){
int satart=0; //开始位置
int end=nums.length;
int mid=-1; //下标
while(satart<=end){
mid=(satart+end)/2;//3
System.out.println(mid);
if(nums[mid]==key){
return mid;
}else if(nums[mid]<key){
satart=mid+1;
}else if(nums[mid]>key){
end=mid-1;
}
}
return -1;
}
}
冒泡排序
public class 冒泡 {
public static void main(String[] args) {
int a[] = { 5, 50, 23, 25, 12, 36, 45 };
int temp;
for (int i = 0; i < a.length; i++) {
for (int j = i + 1; j < a.length; j++) {
if (a[i] > a[j]) {
temp = a[i];
a[i] = a[j];
a[j] = temp;
}
}
}
for (int i = 0; i < a.length; i++)
System.out.println(a[i]);
}
}