算法

二分查找法

int look = 5;
int arr [] = new int[]{-5,-3,0,1,2,3,4,5,6};
//初始值的索引
int head = 0;
//初始值的末索引
int end = arr.length-1;
while(head<=end){
    int middle = (head + end ) / 2;
    if(arr[middle] == look){
        System.out.println(middle);
        break;
  }else if(arr[middle] < look){
        head = middle + 1;
  }else{
        head = middle - 1;
  }
}

 冒泡排序

 

int max;
int pao [] = new int {55,66,32,154,57,1,234,4,68};
for(int i=0;i<pao.length;i++){
   for(int j=0;j<pao.length-i;j++){
       if(pao[j]>pao[j+1]){
          max = pao[j+1];
          pao[j] = pao [j+1];
          pao[j+1] = max;  
      }
   }
}