leetcode: Add 1979

math/src/gcd.cpp

@@ -0,0 +1,19 @@
+// Copyright (c) 2024 Xu Shaohua <[email protected]>. All rights reserved.
+// Use of this source is governed by General Public License that can be found
+// in the LICENSE file.
+
+#include <cassert>
+
+int gcd(int a, int b) {
+  assert(a >= b);
+  if (b == 0) {
+    return a;
+  } else {
+    return gcd(b, a % b);
+  }
+} 
+
+int lcm(int a, int b) {
+  assert(a >= b);
+  return a / gcd(a, b) * b;
+}

src/leetcode/1979.find-greatest-common-divisor-of-array/Cargo.toml

@@ -0,0 +1,7 @@
+[package]
+name = "lc-1979-find-greatest-common-divisor-of-array"
+version = "0.1.0"
+edition = "2021"
+publish = false
+
+[dependencies]

src/leetcode/1979.find-greatest-common-divisor-of-array/Makefile

@@ -0,0 +1,3 @@
+
+build: main.cpp
+	g++ -g main.cpp -o main

src/leetcode/1979.find-greatest-common-divisor-of-array/index.md

@@ -0,0 +1,4 @@
+
+# 1979. 找出数组的最大公约数 Find Greatest Common Divisor of Array
+
+[问题描述](https://leetcode.com/problems/find-greatest-common-divisor-of-array)

src/leetcode/1979.find-greatest-common-divisor-of-array/main.cpp

@@ -0,0 +1,30 @@
+// Copyright (c) 2024 Xu Shaohua <[email protected]>. All rights reserved.
+// Use of this source is governed by General Public License that can be found
+// in the LICENSE file.
+
+#include <cassert>
+
+#include <algorithm>
+#include <vector>
+
+int gcd(int a, int b) {
+  assert(a >= b);
+  if (b == 0) {
+    return a;
+  } else {
+    return gcd(b, a % b);
+  }
+}
+
+class Solution {
+ public:
+  int findGCD(std::vector<int>& nums) {
+    const int min_num = *std::min_element(nums.cbegin(), nums.cend());
+    const int max_num = *std::max_element(nums.cbegin(), nums.cend());
+    return gcd(max_num, min_num);
+  }
+};
+
+int main() {
+  return 0;
+}

src/leetcode/1979.find-greatest-common-divisor-of-array/src/main.rs

@@ -0,0 +1,48 @@
+// Copyright (c) 2024 Xu Shaohua <[email protected]>. All rights reserved.
+// Use of this source is governed by General Public License that can be found
+// in the LICENSE file.
+
+fn gcd(a: i32, b: i32) -> i32 {
+    debug_assert!(a > b && b >= 0);
+    if b == 0 {
+        a
+    } else {
+        gcd(b, a % b)
+    }
+}
+
+pub fn find_gcd1(nums: Vec<i32>) -> i32 {
+    debug_assert!(nums.len() >= 2);
+    let mut min_val = nums[0];
+    let mut max_val = nums[0];
+    for num in nums {
+        if num < min_val {
+            min_val = num;
+        }
+        if num > max_val {
+            max_val = num;
+        }
+    }
+    gcd(max_val, min_val)
+}
+
+pub type SolutionFn = fn(Vec<i32>) -> i32;
+
+fn check_solution(func: SolutionFn) {
+    let nums = vec![2, 5, 6, 9, 10];
+    assert_eq!(func(nums), 2);
+}
+
+fn main() {
+    check_solution(find_gcd1);
+}
+
+#[cfg(test)]
+mod tests {
+    use super::{check_solution, find_gcd1};
+
+    #[test]
+    fn test_find_gcd1() {
+        check_solution(find_gcd1);
+    }
+}