算法题

public class aa {	public static void main(String[] args) {		//求最大公约数以及公倍数		int a=2;		int b=4;		int max=b>a?b:a;		int min=b<a?b:a;		//最小公倍数		for (int i = max; i <=a*b; i++) {			if(i%min==0&&i%max==0){				System.out.PRintln(i);				break;			}		}				//最大公约数		for (int i = min; i >= 1; i--) {			if(min%i==0&&max%i==0){				System.out.println(i);				break;			}		}						//整形数据，有+有-。求出  相邻数字和最大的数字组合  的和		int[] arr=new int[]{1,-2,3,10,-4,7,2,-5};		int sum=0;		int temp=sum;		for (int i : arr) {			temp+=i;			if(temp<0)  temp=0;			if(temp>sum) sum=temp;		}		if(sum==0){			sum=arr[0];			for (int i = 1; i < arr.length; i++) {				if(arr[i]>sum)					sum=arr[i];			}		}		System.out.println(sum);						//冒泡		System.out.print("冒泡排序,原数组为:");		for (int i : arr) {			System.out.print(i+"  ");		}		System.out.print("    排序后:");		for (int i = 0; i < arr.length; i++) {			for (int j = i+1; j < arr.length; j++) {				if(arr[i]<arr[j])					swap(arr,i,j);			}		}		for (int i : arr) {			System.out.print(i+"  ");		}		System.out.println("");						//直接选择		System.out.print("直接选择排序,原数组为:");		for (int i : arr) {			System.out.print(i+"  ");		}		System.out.print("   直接选择排序后:");		for (int i = 0; i < arr.length; i++) {			int index=i;			for (int j = i+1; j < arr.length; j++) {				if(arr[index]>arr[j])					index=j;			}			swap(arr, i, index);		}		for (int i : arr) {			System.out.print(i+"  ");		}		System.out.println("");						//整个字符串反转		String str="abcdefg";		char[] c=str.toCharArray();		int index=c.length;		for (int i = 0; i < c.length/2; i++) {			swap(c, i, index-1);			index--;		}		System.out.println(str+"整个字符串反转:"+String.valueOf(c));		str=String.valueOf(c);		//指定字符串反转		String key="fedcb";//指定的字符串		//取得指定字符串的坐标		int start =str.indexOf(key);		int end=start+key.length();		index=end;		for (int i = start; i < end/2; i++) {			swap(c, i, index-1);			index--;		}		System.out.println(str+"  自定字符串为"+key+"   指定字符串反转:"+String.valueOf(c));				//反转单词顺序 单词不变  如  i am a student.=>student. a am i		str="i am a student.";		String temp1=str;		int WordCount=str.split(" ").length;		String s="";		for (int i = 0; i < wordCount; i++) {			if(true==temp1.contains(" ")){				String buff=temp1.substring(temp1.lastIndexOf(" ")+1,temp1.length());				temp1=temp1.substring(0, temp1.lastIndexOf(" "));				s+=buff+" ";			}else				s+=temp1;		}		System.out.println("反转单词顺序 单词不变 "+str+"反转后:"+s);						//有两个字符串  匹配出最长相同的子串  如 abcdhellocde   seerhellocadasabad  ->helloc		String s1="abcdhellocde";		String s2="sabcdheeerhellocadasabad";		int length=s1.length();		boolean flag=false;		for (int i = length; i > 0&&!flag; i--) { //控制匹配长度			for (int j = 0; j <= length-i; j++) {//控制位置				String buff=s1.substring(j, i+j);				if(s2.contains(buff)){					System.out.println("s1:abcdhellocde,s2:sabcdheeerhellocadasabad 匹配最长相同子串为:"+buff);					flag=true;					continue;//防止有多条一样长度的字符串，没有全部被找到				}			}					}			}		public static void swap(char[] arr,int index1,int index2){		char temp=arr[index1];		arr[index1]=arr[index2];		arr[index2]=temp;	}	public static void swap(int[] arr,int index1,int index2){		int temp=arr[index1];		arr[index1]=arr[index2];		arr[index2]=temp;	}}