Java 判斷兩個字符串是否由相同的字符組成的實例

package CharString;
 
import java.util.HashMap;
import java.util.Map;
 
public class CompareString {
 
	public static boolean compare(char[] a,char[] b){
		int aLen = a.length;
		int bLen = b.length;
		if(aLen!=bLen){
			return false;
		}
		Map<Character,Integer> map = new HashMap<Character,Integer>();
		for(int i=0;i<aLen;i++){
			if(map.containsKey(a[i])){
				map.put(a[i], map.get(a[i])+1);
			}else{
				map.put(a[i], 1);
			}
		}
		for(int j=0;j<bLen;j++){
			if(map.containsKey(a[j])&&map.get(a[j])==1){
				map.remove(a[j]);
			}else{
				map.put(a[j], map.get(a[j])-1);
			}
		}
		return map.isEmpty();
		
	}
	
	public static boolean compare2(String a,String b){
		byte[] b1 = a.getBytes();
		byte[] b2 = b.getBytes();
		int[] bCount = new int[256];
		for(int i=0;i<256;i++){
			bCount[i] = 0;
		}
		for(int i=0;i<b1.length;i++)
			bCount[b1[i]-'0']++;
		for(int i=0;i<b2.length;i++)
			bCount[b2[i]-'0']--;
		for(int i=0;i<256;i++){
			if(bCount[i]!=0)
				return false;
		}
		return true;
	}
	
	public static void main(String[] args) {
		// TODO Auto-generated method stub
 
		StringBuffer s11 = new StringBuffer();
		StringBuffer s22 = new StringBuffer();
		for(int i=0;i<10000;i++){
			s11.append("aybcybayaatt");
		}
		for(int i=0;i<10000;i++){
			s22.append("aybcybayaatt");
		}
		String s1 = s11.toString();
		String s2 = s22.toString();
		char[] a = s1.toCharArray();
		char[] b = s2.toCharArray();
		
		long l3=System.currentTimeMillis();
		System.out.println(compare(a,b));
		long l4=System.currentTimeMillis();
		System.out.println("集合用時："+(l4-l3));
		
		long l1=System.currentTimeMillis();
		System.out.println(compare2(s1,s2));
		long l2=System.currentTimeMillis();
		System.out.println("數(shù)組用時："+(l2-l1));
	}
 
}

true
集合用時：54毫秒
true
數(shù)組用時：17毫秒