From b7984113a37f3cb375a1f3eefaf64b71b61d087d Mon Sep 17 00:00:00 2001
From: Kirito <1362050620@qq.com>
Date: Sat, 13 Aug 2016 12:11:28 +0800
Subject: [PATCH] Create KMP.cpp

---
 .ACM-Templates/KMP.cpp | 35 +++++++++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)
 create mode 100644 .ACM-Templates/KMP.cpp

diff --git a/.ACM-Templates/KMP.cpp b/.ACM-Templates/KMP.cpp
new file mode 100644
index 0000000..65d236e
--- /dev/null
+++ b/.ACM-Templates/KMP.cpp
@@ -0,0 +1,35 @@
+#include <string>
+#include <iostream>
+#include <cstring>
+using namespace std;
+
+void getfill(string s,int* f)
+{
+    //memset(f,0,sizeof(f));  //根据其前一个字母得到
+    for(size_t i=1;i<s.size();i++)
+    {
+        int j=f[i];
+        while(j && s[i]!=s[j])
+            j=f[j];
+        f[i+1]=(s[i]==s[j])?j+1:0;
+    }
+}
+
+int KMP(string a,string s)
+{
+    int* f=new int[s.size()+32];
+    memset(f,0,sizeof(int)*s.size());
+    getfill(s,f);size_t j=0;
+    for(size_t i=0;i<a.size();i++)
+    {
+        while(j && a[i]!=s[j])
+            j=f[j];
+        if(a[i]==s[j])
+            j++;
+        if(j==s.size()){
+            delete[] f;return i-s.size()+1;
+        }
+    }
+    delete[] f;
+    return -1;
+}