diff --git "a/2109020144/chap3/\345\256\236\351\252\2145.cpp" "b/2109020144/chap3/\345\256\236\351\252\2145.cpp"
new file mode 100644
index 0000000000000000000000000000000000000000..7733d56db8c161fd681efd51f077ff9c31cc90af
--- /dev/null
+++ "b/2109020144/chap3/\345\256\236\351\252\2145.cpp"
@@ -0,0 +1,27 @@
+#include<bits/stdc++.h>
+using namespace std;
+int index;
+int maxlen;
+void simplesearch(string s) {
+	string a; 
+	for (int i = 0; i < s.length(); i++) {
+		for (int j = i + 1; j < s.length(); j++) {
+			if (s[i] == s[j]) {
+				int length = 1;
+				for (int k = 1; s[i + k] == s[j + k]; k++) {
+					length++;
+				}
+				if (length > maxlen) {
+					maxlen = length;
+					index = i;
+				}
+			}
+		}
+	}
+}
+int main() {
+	string s = "bananananannana";
+	simplesearch(s);
+	cout << index << " " << maxlen;
+	return 0;
+}
\ No newline at end of file