贪心 +1

Author: hxzhao527

src/array/ext/math.rs

@@ -7,6 +7,7 @@
 //! * 中等
 //!     * [462. 最小操作次数使数组元素相等 II](min_moves2)
 //!     * [667. 优美的排列 II](construct_array)
+//!     * [1759. 统计同构子字符串的数目](count_homogenous)
 
 /// [462. 最少移动次数使数组元素相等 II](https://leetcode.cn/problems/minimum-moves-to-equal-array-elements-ii/)
 ///
@@ -431,7 +432,7 @@ pub fn num_magic_squares_inside(grid: Vec<Vec<i32>>) -> i32 {
 
 /// [1759. 统计同构子字符串的数目](https://leetcode.cn/problems/count-number-of-homogenous-substrings/)
 pub fn count_homogenous(s: String) -> i32 {
-    if s.is_empty(){
+    if s.is_empty() {
         return 0;
     }
 
@@ -442,21 +443,21 @@ pub fn count_homogenous(s: String) -> i32 {
     let mut last = chrs.next().unwrap();
     let mut count: i64 = 1;
 
-    for c in chrs{
-        if last == c{
+    for c in chrs {
+        if last == c {
             count += 1;
             continue;
         }
         let cnt = (count + 1) * count / 2;
         sum = (sum + (cnt % MODULO) as i32) % MODULO as i32;
-        
+
         last = c;
         count = 1;
     }
 
     let cnt = (count + 1) * count / 2;
-    sum = (sum + (cnt % MODULO) as i32)  % MODULO as i32;
-    
+    sum = (sum + (cnt % MODULO) as i32) % MODULO as i32;
+
     sum
 }
 
@@ -466,26 +467,26 @@ mod tests {
     use crate::vec2;
 
     #[test]
-    fn test_count_homogenous(){
-        struct Testcase{
+    fn test_count_homogenous() {
+        struct Testcase {
             s: &'static str,
-            expect: i32
+            expect: i32,
         }
 
         vec![
-            Testcase{
+            Testcase {
                 s: "abbcccaa",
-                expect: 13
-            },
-            Testcase{
-                s: "xy",
-                expect: 2
+                expect: 13,
             },
-            Testcase{
+            Testcase { s: "xy", expect: 2 },
+            Testcase {
                 s: "zzzzz",
-                expect: 15
-            }
-        ].into_iter().enumerate().for_each(|(idx, testcase)| {
+                expect: 15,
+            },
+        ]
+        .into_iter()
+        .enumerate()
+        .for_each(|(idx, testcase)| {
             let Testcase { s, expect } = testcase;
             let actual = count_homogenous(s.to_string());
             assert_eq!(expect, actual, "case {} failed", idx);

src/moreandmore/mod.rs

@@ -11,6 +11,7 @@
 //!     * [455. 分发饼干](find_content_children)
 //!     * [53. 最大子数组和](max_sub_array)
 //!     * [942. 增减字符串匹配](di_string_match)
+//!     *  [2027. 转换字符串的最少操作次数](minimum_moves)
 //! * 中等
 //!     * [376. 摆动序列](wiggle_max_length)
 //!     * [55. 跳跃游戏](can_jump)
@@ -323,22 +324,22 @@ pub fn is_n_straight_hand(hand: Vec<i32>, group_size: i32) -> bool {
     hand.sort();
 
     let mut counter = HashMap::new();
-    for &card in hand.iter(){
+    for &card in hand.iter() {
         *counter.entry(card).or_insert(0) += 1;
     }
 
-    for i in 0..hand.len(){
+    for i in 0..hand.len() {
         let start = hand[i];
-        let e= counter.entry(start).or_default();
-        if *e ==0 {
+        let e = counter.entry(start).or_default();
+        if *e == 0 {
             // 跳过, 下一个
             continue;
         }
         *e -= 1;
-        for i in 1..group_size{
+        for i in 1..group_size {
             // 开始假设枚举
-            let e = counter.entry(start+i).or_default();
-            if *e == 0{
+            let e = counter.entry(start + i).or_default();
+            if *e == 0 {
                 return false;
             }
             *e -= 1;
@@ -347,10 +348,61 @@ pub fn is_n_straight_hand(hand: Vec<i32>, group_size: i32) -> bool {
     true
 }
 
+/// [2027. 转换字符串的最少操作次数](https://leetcode.cn/problems/minimum-moves-to-convert-string/)
+/// 
+/// 只要遇到 X, 三个以内不论什么, 都是至少转换一次
+/// 既然不管是啥都得转换, 那就直接跳过
+pub fn minimum_moves(s: String) -> i32 {
+    let mut sum = 0;
+
+    let bs = s.as_bytes();
+    let mut idx = 0;
+    while idx < bs.len(){
+        if bs[idx] == b'O'{
+            idx += 1;
+            continue;
+        }
+        sum += 1;
+        idx += 3;
+    }
+
+   sum
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
 
+    #[test]
+    fn test_minimum_moves() {
+        struct TestCase {
+            s: &'static str,
+            expect: i32,
+        }
+
+        vec![
+            TestCase {
+                s: "XXX",
+                expect: 1,
+            },
+            TestCase {
+                s: "XXOX",
+                expect: 2,
+            },
+            TestCase {
+                s: "OOOO",
+                expect: 0,
+            },
+        ]
+        .into_iter()
+        .enumerate()
+        .for_each(|(idx, testcase)| {
+            let TestCase { s, expect } = testcase;
+            let actual = minimum_moves(s.to_string());
+            assert_eq!(expect, actual, "case {} failed", idx);
+        });
+    }
+
     #[test]
     fn test_is_n_straight_hand() {
         struct TestCase {