🤖 Daily Challenge: Problem #1404

SOLVED.md

@@ -156,6 +156,7 @@
 | 1390 | [Four Divisors](https://leetcode.com/problems/four-divisors/) | [Code](src/leetcode/problems/four-divisors.cpp) / [Test](test/leetcode/problems/four-divisors.cpp) |
 | 1391 | [Check if There is a Valid Path in a Grid](https://leetcode.com/problems/check-if-there-is-a-valid-path-in-a-grid/) | [Code](src/leetcode/problems/check-if-there-is-a-valid-path-in-a-grid.cpp) / [Test](test/leetcode/problems/check-if-there-is-a-valid-path-in-a-grid.cpp) |
 | 1400 | [Construct K Palindrome Strings](https://leetcode.com/problems/construct-k-palindrome-strings/) | [Code](src/leetcode/problems/construct-k-palindrome-strings.cpp) / [Test](test/leetcode/problems/construct-k-palindrome-strings.cpp) |
+| 1404 | [Number of Steps to Reduce a Number in Binary Representation to One](https://leetcode.com/problems/number-of-steps-to-reduce-a-number-in-binary-representation-to-one/) | [Code](src/leetcode/problems/number-of-steps-to-reduce-a-number-in-binary-representation-to-one.cpp) / [Test](test/leetcode/problems/number-of-steps-to-reduce-a-number-in-binary-representation-to-one.cpp) |
 | 1411 | [Number of Ways to Paint N × 3 Grid](https://leetcode.com/problems/number-of-ways-to-paint-n-3-grid/) | [Code](src/leetcode/problems/number-of-ways-to-paint-n-3-grid.cpp) / [Test](test/leetcode/problems/number-of-ways-to-paint-n-3-grid.cpp) |
 | 1417 | [Reformat The String](https://leetcode.com/problems/reformat-the-string/) | [Code](src/leetcode/problems/reformat-the-string.cpp) / [Test](test/leetcode/problems/reformat-the-string.cpp) |
 | 1418 | [Display Table of Food Orders in a Restaurant](https://leetcode.com/problems/display-table-of-food-orders-in-a-restaurant/) | [Code](src/leetcode/problems/display-table-of-food-orders-in-a-restaurant.cpp) / [Test](test/leetcode/problems/display-table-of-food-orders-in-a-restaurant.cpp) |

include/leetcode/problems/number-of-steps-to-reduce-a-number-in-binary-representation-to-one.h

@@ -0,0 +1,18 @@
+#include "leetcode/core.h"
+
+namespace leetcode {
+namespace problem_1404 {
+
+using Func = std::function<int(string)>;
+
+class NumberOfStepsToReduceANumberInBinaryRepresentationToOneSolution : public SolutionBase<Func> {
+ public:
+  //! 1404. Number of Steps to Reduce a Number in Binary Representation to One
+  //! https://leetcode.com/problems/number-of-steps-to-reduce-a-number-in-binary-representation-to-one/
+  int numSteps(string s);
+
+  NumberOfStepsToReduceANumberInBinaryRepresentationToOneSolution();
+};
+
+}  // namespace problem_1404
+}  // namespace leetcode

src/leetcode/problems/number-of-steps-to-reduce-a-number-in-binary-representation-to-one.cpp

@@ -0,0 +1,52 @@
+#include "leetcode/problems/number-of-steps-to-reduce-a-number-in-binary-representation-to-one.h"
+
+namespace leetcode {
+namespace problem_1404 {
+
+// 模拟二进制操作
+// 从字符串末尾开始处理，维护进位
+// 时间复杂度: O(n), 空间复杂度: O(1)
+static int solution1(string s) {
+  int steps = 0;
+  int carry = 0;
+  int n = s.size();
+
+  // 从后往前处理，除了最高位（s[0]）
+  for (int i = n - 1; i > 0; --i) {
+    int bit = (s[i] - '0') + carry;
+    if (bit % 2 == 0) {
+      // 偶数：除以 2，步骤 +1
+      steps++;
+    } else {
+      // 奇数：加 1，步骤 +2（加1需要1步，除2需要1步）
+      // 加1会产生进位
+      steps += 2;
+      carry = 1;
+    }
+  }
+
+  // 处理最高位
+  int lastBit = (s[0] - '0') + carry;
+  if (lastBit == 2) {
+    // 最高位 1 + carry 1 = 2 (二进制 10)
+    // 还需要一步除以 2 变成 1
+    steps++;
+  }
+  // lastBit == 1 时，已经是 1，不需要额外步骤
+
+  return steps;
+}
+
+NumberOfStepsToReduceANumberInBinaryRepresentationToOneSolution::NumberOfStepsToReduceANumberInBinaryRepresentationToOneSolution() {
+  setMetaInfo({.id = 1404,
+               .title = "Number of Steps to Reduce a Number in Binary Representation to One",
+               .url = "https://leetcode.com/problems/number-of-steps-to-reduce-a-number-in-binary-representation-to-one/"});
+  registerStrategy("Simulation", solution1);
+}
+
+int NumberOfStepsToReduceANumberInBinaryRepresentationToOneSolution::numSteps(string s) {
+  return getSolution()(s);
+}
+
+}  // namespace problem_1404
+}  // namespace leetcode

test/leetcode/problems/number-of-steps-to-reduce-a-number-in-binary-representation-to-one.cpp

@@ -0,0 +1,38 @@
+#include "leetcode/problems/number-of-steps-to-reduce-a-number-in-binary-representation-to-one.h"
+
+#include "gtest/gtest.h"
+
+namespace leetcode {
+namespace problem_1404 {
+
+class NumberOfStepsToReduceANumberInBinaryRepresentationToOneTest : public ::testing::TestWithParam<string> {
+ protected:
+  void SetUp() override { solution.setStrategy(GetParam()); }
+
+  NumberOfStepsToReduceANumberInBinaryRepresentationToOneSolution solution;
+};
+
+TEST_P(NumberOfStepsToReduceANumberInBinaryRepresentationToOneTest, Example1) {
+  string s = "1101";
+  int expected = 6;
+  EXPECT_EQ(expected, solution.numSteps(s));
+}
+
+TEST_P(NumberOfStepsToReduceANumberInBinaryRepresentationToOneTest, Example2) {
+  string s = "10";
+  int expected = 1;
+  EXPECT_EQ(expected, solution.numSteps(s));
+}
+
+TEST_P(NumberOfStepsToReduceANumberInBinaryRepresentationToOneTest, Example3) {
+  string s = "1";
+  int expected = 0;
+  EXPECT_EQ(expected, solution.numSteps(s));
+}
+
+INSTANTIATE_TEST_SUITE_P(
+    LeetCode, NumberOfStepsToReduceANumberInBinaryRepresentationToOneTest,
+    ::testing::ValuesIn(NumberOfStepsToReduceANumberInBinaryRepresentationToOneSolution().getStrategyNames()));
+
+}  // namespace problem_1404
+}  // namespace leetcode