我总结的一些处理问题的方法

1.求质数：for(int i=1;i<100;i++){

                    boolean flag = true;

                    for(int j=2;j<50;j++){

                         if(i%j==0){

                              flag=false;break;

                         }

                    }

                    if(flag) System.out.println(i);

               }

2冒泡排序：for(int i=0;i<arr.length;i++){

                      for(int j=0;j<arr.length-1-i;j++){

                           if(arr[j]>arr[j+1]){

                                   arr[j]=arr[j]+arr[j+1];

                                   arr[j+1]=arr[j]-arr[j+1];

                                   arr[j]=arr[j]-arr[j+1];

                           }

                       }

                 }

评论

1 楼 xiangxuehai_jiaer 2011-09-07  

//求100以内的素数(用开根号的方法)
public class PrimeNumber {

	public static void main(String[] args) {
		
		int i,j,k;
		
		for(i=2;i<100;i++){
			
			k=(int)Math.sqrt(i);
			
			for(j=2;j<=k;j++){
				
				if(i%j==0){
					break;
				}
			}
			
			if(j>k){
				System.out.print(i+" ");
			}
		}
	}
}