From 9012cdebec8d4800b8246660c4309ea14c5250a8 Mon Sep 17 00:00:00 2001
From: chayan das <110921638+Chayandas07@users.noreply.github.com>
Date: Sun, 29 Dec 2024 23:56:02 +0530
Subject: [PATCH] Create 1639. Number of Ways to Form a Target String Given a
 Dictionary

---
 ...to Form a Target String Given a Dictionary | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)
 create mode 100644 1639. Number of Ways to Form a Target String Given a Dictionary

diff --git a/1639. Number of Ways to Form a Target String Given a Dictionary b/1639. Number of Ways to Form a Target String Given a Dictionary
new file mode 100644
index 0000000..c21975e
--- /dev/null
+++ b/1639. Number of Ways to Form a Target String Given a Dictionary	
@@ -0,0 +1,19 @@
+class Solution {
+ public: 
+  int numWays(vector<string>& words, string target) {
+    constexpr int kMod = 1'000'000'007;
+    const int wordLength = words[0].length();
+    vector<long> dp(target.size() + 1);
+    dp[0] = 1;
+    for (int j = 0; j < wordLength; ++j) {
+      vector<int> count(26);
+      for (const string& word : words)
+        ++count[word[j] - 'a'];
+      for (int i = target.size(); i > 0; --i) {
+        dp[i] += dp[i - 1] * count[target[i - 1] - 'a'];
+        dp[i] %= kMod;
+      }
+    }
+    return dp[target.length()];
+  };
+};