diff options
Diffstat (limited to 'string/kmp.cpp')
| -rw-r--r-- | string/kmp.cpp | 36 |
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; +} |
