https://leetcode.cn/problems/count-ways-to-build-good-string

Author: masx200

README.md

@@ -45,6 +45,8 @@ Step 2. Add the dependency
 
 <summary>展开查看</summary>
 
+https://leetcode.cn/problems/count-ways-to-build-good-string
+
 https://leetcode.cn/problems/number-of-distinct-averages
 
 https://leetcode.cn/problems/custom-sort-string

count-ways-to-build-good-string/index.ts

@@ -0,0 +1,19 @@
+function countGoodStrings(
+    low: number,
+    high: number,
+    zero: number,
+    one: number,
+): number {
+    const dp: number[] = Array(high + 1).fill(0);
+    dp[0] = 1;
+    const mod = 1e9 + 7;
+    let ans = 0;
+    for (let i = 0; i <= high; i++) {
+        if (i >= zero) dp[i] += dp[i - zero];
+        if (i >= one) dp[i] += dp[i - one];
+        dp[i] %= mod;
+        if (i >= low) ans = (ans + dp[i]) % mod;
+    }
+    return ans;
+}
+export default countGoodStrings;