Added KMP algorithm implementation in java

KMP.java

@@ -0,0 +1,72 @@
+public class KMP {
+
+    public boolean hasSubstring(char[] text, char[] pattern){
+        int i=0;
+        int j=0;
+        int k = 0;
+        while(i < text.length && j < pattern.length){
+            if(text[i] == pattern[j]){
+                i++;
+                j++;
+            }else{
+                j=0;
+                k++;
+                i = k;
+            }
+        }
+        if(j == pattern.length){
+            return true;
+        }
+        return false;
+    }
+    private int[] computeTemporaryArray(char pattern[]){
+        int [] lps = new int[pattern.length];
+        int index =0;
+        for(int i=1; i < pattern.length;){
+            if(pattern[i] == pattern[index]){
+                lps[i] = index + 1;
+                index++;
+                i++;
+            }else{
+                if(index != 0){
+                    index = lps[index-1];
+                }else{
+                    lps[i] =0;
+                    i++;
+                }
+            }
+        }
+        return lps;
+    }
+    public boolean KMP(char []text, char []pattern){
+        int lps[] = computeTemporaryArray(pattern);
+        int i=0;
+        int j=0;
+        while(i < text.length && j < pattern.length){
+            if(text[i] == pattern[j]){
+                i++;
+                j++;
+            }else{
+                if(j!=0){
+                    j = lps[j-1];
+                }else{
+                    i++;
+                }
+            }
+        }
+        if(j == pattern.length){
+            return true;
+        }
+        return false;
+    }
+
+    public static void main(String args[]){
+
+        String str = "abcxabcdabcdabcy";
+        String subString = "abcdabcy";
+        KMP ss = new KMP();
+        boolean result = ss.KMP(str.toCharArray(), subString.toCharArray());
+        System.out.print(result);
+
+    }
+}