Exercise2

Exercise/Homework2/Q1.cpp

@@ -0,0 +1,43 @@
+#include <iostream>
+#include <string>
+using namespace std;
+
+int map(char c) {
+    if (c == '{') return 4;
+    if (c == '[') return 3;
+    if (c == '(') return 2;
+    if (c == '<') return 1;
+    return 0;
+}
+
+bool match(char a, char b) {
+    return (a == '(' && b == ')') || (a == '[' && b == ']') || (a == '{' && b == '}') || (a == '<' && b == '>');
+}
+
+bool check(const string& s) {
+    string front;
+    for (int i = 0; i < s.size(); i++) {
+        if (s[i] == '{' || s[i] == '[' || s[i] == '(' || s[i] == '<') {
+            if (!front.empty() && map(front.back()) <= map(s[i]))
+                return false;
+            front.push_back(s[i]);
+        } else if (s[i] == '}' || s[i] == ']' || s[i] == ')' || s[i] == '>') {
+            if (front.empty() || !match(front.back(), s[i]))
+                return false;
+            front.pop_back();
+        }
+    }
+    return front.empty();
+}
+
+int main() {
+    int n;
+    cin >> n;
+    for (int i = 0; i < n; i++) {
+        string s;
+        cin >> s;
+        cout << (check(s) ? "Match" : "Fail") << endl;
+    }
+    return 0;
+}
+

Exercise/Homework2/Q2.rs

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+use std::io::{self, Read, Write};
+
+fn main() {
+/*
+    let mut s = String::new();
+    io::stdin().read_line(&mut s).unwrap();
+    let n: usize = s.trim().parse().unwrap();
+
+    let mut nums: Vec<i64> = Vec::new();
+    let mut max: i64 = 0;
+
+    for _ in 0..n {
+        let mut x = String::new();
+        io::stdin().read_line(&mut x).unwrap();
+        let a: i64 = x.trim().parse().unwrap();
+        nums.push(a);
+        if a > max {
+            max = a;
+}*/
+//  //输入太慢了过不了
+    let mut buf = String::new();
+    io::stdin().read_to_string(&mut buf).unwrap();
+    let mut it = buf.split_whitespace();
+
+    let m: usize = it.next().unwrap().parse().unwrap();
+    let mut vec: Vec<i64> = Vec::with_capacity(m);
+    let mut max: i64 = 0;
+
+    for _ in 0..m {
+        let a: i64 = it.next().unwrap().parse().unwrap();
+        vec.push(a);
+        if a > max { max = a; }
+    }
+
+    let mut dp: Vec<i64> = vec![0; (max + 1) as usize];
+    if max >= 0 { dp[0] = 1; }
+    if max >= 1 { dp[1] = 1; }
+    if max >= 2 { dp[2] = 2; }
+    if max >= 3 { dp[3] = 4; }
+
+    for i in 4..=max {
+        dp[i as usize] = dp[(i - 1) as usize] + dp[(i - 2) as usize] + dp[(i - 3) as usize] + dp[(i - 4) as usize];
+    }
+
+    let mut out = String::new();
+    for i in vec {
+        out.push_str(&format!("{}\n", dp[i as usize]));
+    }
+    io::stdout().write_all(out.as_bytes()).unwrap();
+}

Exercise/Homework2/Q3.rs

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+use std::io;
+
+pub struct Status{
+    pos: i32,
+    a: char, // from
+    b: char, // to
+    c: char  // aux
+}
+
+
+fn main(){
+    let mut s = String::new();
+    io::stdin().read_line(&mut s).unwrap();
+    let n: i32 = s.trim().parse().unwrap();
+
+    let mut stack: Vec<Status> = Vec::new();
+    stack.push(Status{pos: n, a: 'A', b: 'C', c: 'B'});
+    let mut max = 0;
+
+    let mut output = String::new(); //输出，要不然太慢总会超时
+
+    while !stack.is_empty() {
+        if stack.len() > max {
+            max = stack.len();
+        }
+
+        let mut end = stack.pop().unwrap();
+        if end.pos == 1 {
+            output.push_str(&format!("Move disk from {} to {}\n", end.a, end.b));
+        } else {
+            stack.push(Status{pos: end.pos - 1, a: end.c, b: end.b, c: end.a});
+            stack.push(Status{pos: 1, a: end.a, b: end.b, c: end.c});
+            stack.push(Status{pos: end.pos - 1, a: end.a, b: end.c, c: end.b});
+
+        }
+    }
+    print!("{}", output);
+    println!("{}", max);
+}