744. 寻找比目标字母大的最小字母

src/main.rs

@@ -1,45 +1,27 @@
 struct Solution;
 mod arr;
 impl Solution {
-    fn get_min(num: i32) -> i32 {
-        let mut chars: Vec<char> = vec![];
-        let mut write_in = false;
-        let mut one_count = 0;
-        for c in format!("{:b}", num).chars().rev() {
-            if write_in {
-                chars.push(c);
-                continue;
-            }
-            if c == '0' {
-                if one_count == 0 {
-                    return -1;
+    pub fn next_greatest_letter(letters: Vec<char>, target: char) -> char {
+        let mut index = 1e5 as usize;
+        for i in 0..letters.len() {
+            if letters[i] > target {
+                if index == 1e5 as usize {
+                    index = i;
+                } else {
+                    if letters[i] < letters[index] {
+                        index = i;
+                    }
                 }
-                for _ in 0..one_count -1 {
-                    chars.push('1');
-                }
-                one_count = 0;
-                chars.push('0');
-                chars.push(c);
-                write_in = true;
-                continue;
             }
-            one_count += 1;
         }
-        let mut ans = 0;
-        if one_count > 0 {
-            return num >> 1;
+        if index == 1e5 as usize {
+            letters[0]
+        } else {
+            letters[index]
         }
-        for c in chars.into_iter().rev() {
-            ans = ans * 2 + c as i32 - '0' as i32;
-        }
-        ans
-    }
-    pub fn min_bitwise_array(nums: Vec<i32>) -> Vec<i32> {
-        nums.into_iter().map(|x| Solution::get_min(x)).collect()
     }
 }
-
 fn main() {
-    let result = Solution::min_bitwise_array(vec![11,13,31]);
+    let result = Solution::next_greatest_letter(vec!['c', 'f', 'j'], 'a');
     println!("{:?}", result);
 }