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-rw-r--r--string/kmp.cpp36
1 files changed, 35 insertions, 1 deletions
diff --git a/string/kmp.cpp b/string/kmp.cpp
index 7898192..f7c3630 100644
--- a/string/kmp.cpp
+++ b/string/kmp.cpp
@@ -1 +1,35 @@
-a
+#include <iostream>
+#include <vector>
+
+using namespace std;
+
+//Preprocessing Substring sub for KMP-Search
+vector<int> kmp_preprocessing(string& sub) {
+ vector<int> b(sub.size() + 1);
+ b[0] = -1;
+ int i = 0, j = -1;
+ while(i < sub.size()) {
+ while(j >= 0 && sub[i] != sub[j])
+ j = b[j];
+ i++; j++;
+ b[i] = j;
+ }
+ return b;
+}
+
+//Searching after Substring sub in s
+vector<int> kmp_search(string& s, string& sub) {
+ vector<int> pre = kmp_preprocessing(sub);
+ vector<int> result;
+ int i = 0, j = -1;
+ while(i < s.size()) {
+ while(j >= 0 && s[i] != sub[j])
+ j = pre[j];
+ i++; j++;
+ if(j == sub.size()) {
+ result.push_back(i-j);
+ j = pre[j];
+ }
+ }
+ return result;
+}