Add solution and test-cases for problem 1513

leetcode/1501-1600/1513.Number-of-Substrings-With-Only-1s/README.md

@@ -1,28 +1,34 @@
 # [1513.Number of Substrings With Only 1s][title]
 
-> [!WARNING|style:flat]
-> This question is temporarily unanswered if you have good ideas. Welcome to [Create Pull Request PR](https://github.com/kylesliu/awesome-golang-algorithm)
-
 ## Description
+Given a binary string `s`, return the number of substrings with all characters `1`'s. Since the answer may be too large, return it modulo `10^9 + 7`.
 
 **Example 1:**
 
 ```
-Input: a = "11", b = "1"
-Output: "100"
+Input: s = "0110111"
+Output: 9
+Explanation: There are 9 substring in total with only 1's characters.
+"1" -> 5 times.
+"11" -> 3 times.
+"111" -> 1 time.
 ```
 
-## 题意
-> ...
-
-## 题解
+**Example 2:**
 
-### 思路1
-> ...
-Number of Substrings With Only 1s
-```go
+```
+Input: s = "101"
+Output: 2
+Explanation: Substring "1" is shown 2 times in s.
 ```
 
+**Example 3:**
+
+```
+Input: s = "111111"
+Output: 21
+Explanation: Each substring contains only 1's characters.
+```
 
 ## 结语
 

leetcode/1501-1600/1513.Number-of-Substrings-With-Only-1s/Solution.go

@@ -1,5 +1,20 @@
 package Solution
 
-func Solution(x bool) bool {
-	return x
+const mod1513 = 1e9 + 7
+
+func Solution(s string) int {
+	one := 0
+	ans := 0
+	for _, b := range s {
+		if b == '0' {
+			// 1111
+			// 4 3 2 1
+			ans = (ans + one*(one+1)/2) % mod1513
+			one = 0
+			continue
+		}
+		one++
+	}
+	ans = (ans + one*(one+1)/2) % mod1513
+	return ans
 }

leetcode/1501-1600/1513.Number-of-Substrings-With-Only-1s/Solution_test.go

@@ -10,12 +10,12 @@ func TestSolution(t *testing.T) {
 	//	测试用例
 	cases := []struct {
 		name   string
-		inputs bool
-		expect bool
+		inputs string
+		expect int
 	}{
-		{"TestCase", true, true},
-		{"TestCase", true, true},
-		{"TestCase", false, false},
+		{"TestCase1", "0110111", 9},
+		{"TestCase2", "101", 2},
+		{"TestCase3", "111111", 21},
 	}
 
 	//	开始测试
@@ -30,10 +30,10 @@ func TestSolution(t *testing.T) {
 	}
 }
 
-//	压力测试
+// 压力测试
 func BenchmarkSolution(b *testing.B) {
 }
 
-//	使用案列
+// 使用案列
 func ExampleSolution() {
 }