20240522 Finished

src/problem/mod.rs

@@ -136,4 +136,5 @@ mod p57_insert_interval;
 mod p452_minimum_number_of_arrows_to_burst_balloons;
 mod p71_simplify_path;
 mod p155_min_stack;
-mod p150_evaluate_reverse_polish_notation;
+mod p150_evaluate_reverse_polish_notation;
+mod p224_basic_calculator;

src/problem/p224_basic_calculator.rs

@@ -0,0 +1,63 @@
+/**
+ * [224] Basic Calculator
+ */
+pub struct Solution {}
+
+
+// submission codes start here
+
+impl Solution {
+    pub fn calculate(s: String) -> i32 {
+        let mut operator_stack = vec![1];
+        let mut result: i64 = 0;
+        let mut sign = 1;
+
+        let s : Vec<char> = s.chars().collect();
+
+        let mut i = 0;
+
+        while i < s.len() {
+            if s[i] == ' ' {
+                i += 1;
+            } else if s[i] == '+' {
+                sign = *operator_stack.last().unwrap();
+                i += 1;
+            } else if s[i] == '-' {
+                sign = -(*operator_stack.last().unwrap());
+                i += 1;
+            } else if s[i] == '(' {
+                operator_stack.push(sign);
+                i += 1;
+            } else if s[i] == ')' {
+                operator_stack.pop();
+                i += 1;
+            } else {
+                let mut num: i64 = 0;
+
+                while i < s.len() && s[i].is_numeric() {
+                    num = num * 10 + s[i].to_digit(10).unwrap() as i64;
+                    i += 1;
+                }
+
+                result += sign * num;
+            }
+        }
+
+        result as i32
+    }
+}
+
+// submission codes end
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_224() {
+        assert_eq!(2, Solution::calculate("1 + 1".to_owned()));
+        assert_eq!(3, Solution::calculate(" 2-1 + 2 ".to_owned()));
+        assert_eq!(23, Solution::calculate("(1+(4+5+2)-3)+(6+8)".to_owned()));
+        assert_eq!(2147483647, Solution::calculate("2147483647".to_owned()));
+    }
+}