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-rw-r--r--content/string/kmp.cpp20
1 files changed, 20 insertions, 0 deletions
diff --git a/content/string/kmp.cpp b/content/string/kmp.cpp
new file mode 100644
index 0000000..421479e
--- /dev/null
+++ b/content/string/kmp.cpp
@@ -0,0 +1,20 @@
+vector<int> kmpPreprocessing(const string& sub) {
+ vector<int> b(sz(sub) + 1);
+ b[0] = -1;
+ for (int i = 0, j = -1; i < sz(sub);) {
+ while (j >= 0 && sub[i] != sub[j]) j = b[j];
+ b[++i] = ++j;
+ }
+ return b;
+}
+vector<int> kmpSearch(const string& s, const string& sub) {
+ vector<int> result, pre = kmpPreprocessing(sub);
+ for (int i = 0, j = 0; i < sz(s);) {
+ while (j >= 0 && s[i] != sub[j]) j = pre[j];
+ i++; j++;
+ if (j == sz(sub)) {
+ result.push_back(i - j);
+ j = pre[j];
+ }}
+ return result;
+}