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