Add Z-algorithm

Author: coderick14

z_algorithm.cpp

@@ -0,0 +1,32 @@
+#include <bits/stdc++.h>
+#define ll long long
+using namespace std;
+
+vector<ll> z_function(const string& s) {
+	ll n = s.length();
+	vector<ll> z(n);
+
+	for (ll i = 1, l = 0, r = 0; i < n; i++) {
+		if (i <= r) {
+			z[i] = min(z[i-l], r-i+1);
+		}
+		while (i + z[i] < n and s[z[i]] == s[i+z[i]]) {
+			++z[i];
+		}
+		if (i + z[i] - 1 > r) {
+			l = i, r = i + z[i] - 1;
+		}
+	}
+	return z;
+}
+
+int main() {
+	string s("aabaaba");
+	auto z = z_function(s);
+
+	cout << s << endl;
+	for (auto val : z) {
+		cout << val << " ";
+	}
+	return 0;
+}