使用詞頻來計算兩個語句的相似度，假設語句已經使用分詞工具分好

	public class Similar {
	

		public static double getSimilarity(Vector<String> T1, Vector<String> T2) throws Exception {
		    int size = 0 , size2 = 0 ;
		    double sum=0;
		    if ( T1 != null && ( size = T1.size() ) > 0 && T2 != null && ( size2 = T2.size() ) > 0 ) {
		         
		    	Set<String> set=new HashSet<String>();
		     	Map<String, Integer> s1 = new HashMap<String, Integer>();
		    	Map<String, Integer> s2= new HashMap<String, Integer>();
		    	//獲取T1，T2所有的不重複單詞
		    	for (int i = 0; i < size; i++) {
					set.add(T1.get(i));
				}
		    	for(int j=0;j<size2;j++){
		    		set.add(T2.get(j));
		    		
		    	}
		    	//計算每個向量中的詞語出現的次數
		    	 for (String string : set) {
		    		int count=0;
		    	    int count1=0;
					for (String a1 : T1) {
						if (a1.equals(string)) {
							count++;
						}
					}
					for (String a2 : T2) {
						if (a2.equals(string)) {
							count1++;
						}
					}
					s1.put(string, count);
					s2.put(string, count1);
				}
			
		        //計算百分比
		    	 int c1 = 0 , c2 = 0;
		    	 double sum1 = 0;  //S1、S2
		    	 double b1=0,b2=0;
		    	 for (String string : set) {
		    		 	c1=s1.get(string);
		            	c2=s2.get(string);
		            	 sum1+=c1*c2;
		            	 b1+=c1*c1;
		            	 b2+=c2*c2;
		           		 
		    		 
					
				}
		            sum=sum1/Math.sqrt(b1*b2);
		    }else {
				System.out.println("引數有誤");
			}
			return sum;
		  
			
		}
		public static void main(String[] args) {
			Vector<String> T1 = new Vector<String>() ;//對輸入進行分詞
			Vector<String> T2 = new Vector<String>() ;//對輸入進行分詞
			
			T1.add("i");
			T1.add("kill");
			T1.add("you");
			T1.add("kill");
			T1.add("you");
			T1.add("fop");
			T1.add("tip");
			T1.add("cnce");

			
			T2.add("kill");
			T2.add("you"); 

			try {
				System.out.println(getSimilarity(T1, T2));
			} catch (Exception e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
			
			
		}

	}