From 6011184b37f9e1d661edef1b124b5e195ef55bd9 Mon Sep 17 00:00:00 2001
From: fwqaaq <fwqaaq@gmail.com>
Date: Tue, 25 Jul 2023 00:18:19 +0800
Subject: [PATCH] =?UTF-8?q?Update=200647.=E5=9B=9E=E6=96=87=E5=AD=90?=
 =?UTF-8?q?=E4=B8=B2.md?=
MIME-Version: 1.0
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---
 problems/0647.回文子串.md | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/problems/0647.回文子串.md b/problems/0647.回文子串.md
index 35396192..52f12d9b 100644
--- a/problems/0647.回文子串.md
+++ b/problems/0647.回文子串.md
@@ -519,6 +519,24 @@ function expandRange(s: string, left: number, right: number): number {
 
 Rust：
 
+```rust
+impl Solution {
+    pub fn count_substrings(s: String) -> i32 {
+        let mut dp = vec![vec![false; s.len()]; s.len()];
+        let mut res = 0;
+
+        for i in (0..s.len()).rev() {
+            for j in i..s.len() {
+                if s[i..=i] == s[j..=j] && (j - i <= 1 || dp[i + 1][j - 1]) {
+                    dp[i][j] = true;
+                    res += 1;
+                }
+            }
+        }
+        res
+    }
+}
+```
 
 > 双指针