8. 字符串转换整数 (atoi)

src/main.rs

@@ -3,62 +3,50 @@ mod tree;
 
 struct Solution {}
 impl Solution {
-    pub fn min_window(s: String, t: String) -> String {
-        let s = s.chars().collect::<Vec<char>>();
-        let t = t.chars().collect::<Vec<char>>();
-        if t.len() == 1 && s[0] == t[0] {
-            return t.iter().collect();
-        }
-        let mut arr2 = vec![0; 123];
-        let mut arr1 = vec![0; 123];
-        // 65-90 97-122
-        //return "".to_string();
-        for c in t.iter() {
-            arr2[*c as usize] += 1;
-        }
-        //        let (mut l, mut r)= (-1, -1)
-        let mut ans = 10000000;
-        let mut ans_index = 100000000;
-        let mut l = 0;
-        let mut is_find_ans = false;
-        for r in 0..s.len() {
-            let cur = s[r] as usize;
-            arr1[cur] += 1;
-            if (is_find_ans && s[l] as usize == cur || !is_find_ans) && arr1[cur] >= arr2[cur] {
-                if || -> bool {
-                    for i in 65..=90 {
-                        if arr1[i] < arr2[i] {
-                            return false;
-                        }
-                    }
-                    for i in 97..=122 {
-                        if arr1[i] < arr2[i] {
-                            return false;
-                        }
-                    }
-                    return true;
-                }() {
-                    while arr1[s[l] as usize] > arr2[s[l] as usize] {
-                        arr1[s[l] as usize] -= 1;
-                        l += 1;
-                    }
-                    is_find_ans = true;
-                    if r - l + 1 < ans {
-                        ans = r - l + 1;
-                        ans_index = l;
-                    }
-                }
+    pub fn my_atoi(s: String) -> i32 {
+        let mut ans = 0_i64;
+        let mut neg = false;
+        let s = s.chars().collect::<Vec<_>>();
+        let mut start = 0;
+        for i in 0..s.len() {
+            if s[i] == ' ' {
+                start = i + 1;
+                continue;
             }
+            start = i + if s[i] == '+' || s[i] == '-' {
+                if s[i] == '-' {
+                    neg = true
+                }
+                1
+            } else {
+                0
+            };
+            break;
         }
-        if ans_index == 100000000 {
-            return "".to_string();
+        for i in start..s.len() {
+            if s[i] == '0' {
+                start = i + 1;
+                continue;
+            }
+            break;
         }
-        s[ans_index..ans_index + ans].iter().collect()
+        for i in start..s.len() {
+            let c = s[i];
+            if c.is_ascii_digit() {
+                ans = ans * 10 + if neg { -1 } else { 1 } * (c as u8 - '0' as u8) as i64;
+                if ans > i32::MAX as i64 {
+                    return i32::MAX;
+                }
+                if ans < i32::MIN as i64 {
+                    return i32::MIN;
+                }
+                continue;
+            }
+            break;
+        }
+        ans as i32
     }
 }
 fn main() {
-    println!(
-        "{:?}",
-        Solution::min_window("cabwefgewcwaefgcf".to_string(), "cae".to_string())
-    );
+    println!("{:?}", Solution::my_atoi("1337c0d3".to_string()));
 }