冒泡排序、選擇排序、二分查找

//冒泡排序
public class Test01 {
public static void main(String[] args) {
int[] arr = {1,2,432,32,54,32,3,7,657,563,25,43,6,463,52};
//比較的輪數
for (int i = 0; i < arr.length-1; i++) {
//每輪比較的次數
for (int i1 = 0; i1 < arr.length-1-i; i1++) {
if(arr[i1]>arr[i1+1]){
int tep = arr[i1];
arr[i1]=arr[i1+1];
arr[i1+1]=tep;
}
}
}
System.out.println(Arrays.toString(arr));
}
}

//選擇排序
public class Test02 {
public static void main(String[] args) {
int[] arr = {1,2,432,32,54,32,3,7,657,563,25,43,6,463,52};
for (int i = 0; i < arr.length-1; i++) {
for (int i1 =i+1; i1 < arr.length; i1++) {
if(arr[i]>arr[i1]){
int tep = arr[i];
arr[i] = arr[i1];
arr[i1] = tep;
}
}
}
System.out.println(Arrays.toString(arr));
}
}

//二分查找前提是數組中的數值是有序的
public class Test03 {
public static void main(String[] args) {
int[] arr = {1,2,3,4,32,54,563};
int k = 54;
int key = select(arr,k);
System.out.println(key);
}
public static int select(int[] arr, int k){
int left = 0;
int right = arr.length-1;
while (left<right){
int middle = (left+right)/2;
if(arr[middle]<k){
left=middle+1;
}
else if (arr[middle]>k){
right=middle-1;
}
else {
return middle;
}

    }
    return-1;
}

}