kmp

Author: offamitkumar

String Matching/kmp.cpp

@@ -0,0 +1,35 @@
+
+
+vector<int>table;
+
+void pre(string&a){
+    table.assign(a.size() , 0);
+    table[0] =-1;
+    int j=-1 , i = 0;
+    while(i < (int)a.size()){
+        while(j>=0 && a[i] != a[j]){
+            j = table[j];
+        }
+        ++j;
+        ++i;
+        table[i] = j;
+    }
+}
+
+void search(string &a , string &b){
+    pre(a);
+    int i=0 , j = 0;
+    while(i < (int)b.size()){
+        while(j >= 0 && b[i] != a[j]){
+            j = table[j];
+        }
+        ++j;
+        ++i;
+        if(j==(int)a.size()){
+            cout << i - j << ' ' ;
+            j = table[j];
+        }
+    }
+    cout << '\n'; 
+} 
+