Add solution for codeforces round 983

codeforces/round-983/task_a/Cargo.lock

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+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "task_a"
+version = "0.1.0"

codeforces/round-983/task_a/Cargo.toml

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+[package]
+name = "task_a"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]

codeforces/round-983/task_a/README.md

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+# A. Circuit
+
+[Codeforces](https://codeforces.com/contest/2032/problem/A)
+
+Alice has just crafted a circuit with `n` lights and `2n` switches.
+Each component (a light or a switch) has two states: on or off. The lights and switches are arranged in a way that:
+
+- Each light is connected to exactly two switches.
+- Each switch is connected to exactly one light. It's unknown which light each switch is connected to.
+- When all switches are off, all lights are also off.
+- If a switch is toggled (from on to off, or vice versa), the state of the light connected to it will also toggle. 
+
+Alice brings the circuit, which shows only the states of the `2n` switches, to her sister Iris and gives her a riddle:
+what is the minimum and maximum number of lights that can be turned on?
+
+Knowing her little sister's antics too well, Iris takes no more than a second to give Alice a correct answer.
+Can you do the same?
+
+
+## Input
+
+Each test consists of multiple test cases. The first line contains a single integer `t` (1 ≤ `t` ≤ 500) — the number of test cases.
+The description of the test cases follows.
+
+The first line of each test case contains a single integer `n` (1 ≤ `n` ≤ 50) — the number of lights in the circuit.
+
+The second line of each test case contains `2n` integers `a1`, `a2`, `…` , `a2n` (0 ≤ `ai` ≤ 1) — the states of the switches in the circuit.
+`ai` = 0 means the i-th switch is off, and `ai` = 1 means the i-th switch is on.
+
+
+## Output
+
+For each test case, output two integers — the minimum and maximum number of lights, respectively, that can be turned on.
+
+
+## Example
+
+Input
+
+```
+5
+1
+0 0
+1
+0 1
+1
+1 1
+3
+0 0 1 0 1 0
+3
+0 1 1 1 0 0
+```
+
+Output
+
+```
+0 0
+1 1
+0 0
+0 2
+1 3
+```
+
+
+## Note
+
+In the first test case, there is only one light in the circuit, and no switch is on, so the light is certainly off.
+
+In the second test case, there is only one light in the circuit, but one switch connected to it is on, so the light is on.
+
+In the third test case, there is only one light in the circuit, and both switches are on, so the light is off as it was toggled twice.
+
+In the fourth test case, to have no lights on, the switches can be arranged in this way:
+
+- Switch 1 and switch 4 are connected to light 1. Since both switches are off, light 1 is also off.
+- Switch 2 and switch 6 are connected to light 2. Since both switches are off, light 2 is also off.
+- Switch 3 and switch 5 are connected to light 3. Both switches are on, so light 3 is toggled twice from its initial off state, and thus also stays off. 
+
+And to have 2 lights on, the switches can be arranged in this way:
+
+- Switch 1 and switch 2 are connected to light 1. Since both switches are off, light 1 is also off.
+- Switch 3 and switch 4 are connected to light 2. Since switch 3 is on and switch 4 is off, light 2 is toggled once from its initial off state, so it is on.
+- Switch 5 and switch 6 are connected to light 3. Since switch 5 is on and switch 6 is off, light 3 is toggled once from its initial off state, so it is on. 

codeforces/round-983/task_a/src/main.rs

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+use std::cmp;
+use std::io;
+
+fn calc_min_max(switches: Vec<u8>) -> (u64, u64) {
+    let mut zeros: u64 = 0;
+    let mut ones: u64 = 0;
+
+    switches.iter().for_each(|el| {
+        if *el == 0 {
+            zeros += 1;
+        } else {
+            ones += 1;
+        }
+    });
+
+    (zeros % 2, cmp::min(zeros, ones))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_samples() {
+        assert_eq!(calc_min_max(vec!(0, 0)), (0, 0));
+        assert_eq!(calc_min_max(vec!(0, 1)), (1, 1));
+        assert_eq!(calc_min_max(vec!(1, 1)), (0, 0));
+        assert_eq!(calc_min_max(vec!(0, 0, 1, 0, 1, 0)), (0, 2));
+        assert_eq!(calc_min_max(vec!(0, 1, 1, 1, 0, 0)), (1, 3));
+    }
+}
+
+fn main() {
+    let stdin = io::stdin();
+    let mut buf = String::new();
+    stdin.read_line(&mut buf).unwrap();
+    let t: u64 = buf.trim().parse().unwrap();
+
+    for _i in 0..t {
+        buf.clear();
+        stdin.read_line(&mut buf).unwrap();
+
+        buf.clear();
+        stdin.read_line(&mut buf).unwrap();
+        let switches: Vec<u8> = buf
+            .trim()
+            .split_whitespace()
+            .map(|s| s.parse::<u8>().unwrap())
+            .collect();
+
+        let (min, max) = calc_min_max(switches);
+        println!("{} {}", min, max);
+    }
+}