leetcode: Add 0846

src/leetcode/0846.hand-of-straights/Cargo.toml

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+[package]
+name = "lc-0846-hand-of-straights"
+version = "0.1.0"
+edition = "2021"
+publish = false
+
+[dependencies]

src/leetcode/0846.hand-of-straights/index.md

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+
+# 
+
+[问题描述](../problems/)

src/leetcode/0846.hand-of-straights/src/main.rs

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+// 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.
+
+use std::collections::BTreeMap;
+
+// BTreeMap
+// 计数, 并保证 key 是有序的
+pub fn is_n_straight_hand1(hand: Vec<i32>, group_size: i32) -> bool {
+    let nums = hand;
+    let k = group_size;
+
+    assert!(k >= 1 && k as usize <= nums.len());
+    let k_usize = k as usize;
+
+    // 处理边角情况.
+    if nums.len() % k_usize != 0 {
+        return false;
+    }
+
+    let mut nums = nums;
+    nums.sort_unstable();
+
+    let mut map: BTreeMap<i32, usize> = BTreeMap::new();
+    for &num in &nums {
+        *map.entry(num).or_default() += 1;
+    }
+
+    // 遍历所有的整数.
+    for &num in &nums {
+        // 计数到0, 用完了.
+        if map[&num] == 0 {
+            continue;
+        }
+        for offset in 0..k {
+            let next_num: i32 = offset + num;
+            match map.get_mut(&next_num) {
+                Some(count) if *count > 0 => {
+                    *count -= 1;
+                }
+                // 计数到0, 用完了;
+                // 或者整数就不存在, 无法成组
+                _ => return false,
+            }
+        }
+    }
+
+    true
+}
+
+// TODO(Shaohua): BinaryHeap
+
+pub type SolutionFn = fn(Vec<i32>, i32) -> bool;
+
+fn check_solution(func: SolutionFn) {
+    let hand = vec![1, 2, 3, 6, 2, 3, 4, 7, 8];
+    let group_size = 3;
+    assert!(func(hand, group_size));
+
+    let hand = vec![1, 2, 3, 4, 5];
+    let group_size = 4;
+    assert!(!func(hand, group_size));
+}
+
+fn main() {
+    check_solution(is_n_straight_hand1);
+}
+
+#[cfg(test)]
+mod tests {
+    use super::{check_solution, is_n_straight_hand1};
+
+    #[test]
+    fn test_is_n_straight_hand1() {
+        check_solution(is_n_straight_hand1);
+    }
+}