src/bin/add-strings.rs

Author: bestgopher

src/bin/add-strings.rs

@@ -0,0 +1,45 @@
+fn main() {}
+
+struct Solution;
+
+impl Solution {
+    pub fn add_strings(num1: String, num2: String) -> String {
+        let mut i = 0u8; // 进制
+        let (num1, num2) = (num1.as_bytes(), num2.as_bytes());
+        let (mut i1, mut i2) = (num1.len(), num2.len());
+
+        let mut v = vec![0u8; i1.max(i2) + 1];
+        let mut vindex = v.len() - 1;
+
+        loop {
+            let a = if i1 == 0 && i2 == 0 {
+                break;
+            } else if i1 == 0 && i2 > 0 {
+                i2 -= 1;
+                num2[i2] - b'0' + i
+            } else if i1 > 0 && i2 == 0 {
+                i1 -= 1;
+                num1[i1] - b'0' + i
+            } else {
+                i2 -= 1;
+                i1 -= 1;
+                num1[i1] + num2[i2] -b'0' + i
+            };
+
+            if a >= 10 {
+                v[vindex] = a - 10;
+                i = 1;
+            } else {
+                v[vindex] = a;
+                i = 0;
+            }
+
+            vindex -= 1;
+        }
+
+        v[vindex..].iter().fold(String::with_capacity((&v[vindex..]).len()), |mut x, y| {
+            x.push_str(&*y.to_string());
+            x
+        })
+    }
+}