Min Stack — DSA Interview 150 · Stack
Classic interview problem #155.
Input (stdin)
Line 1: n ops\nNext lines: push x | pop | top | getMin
Output (stdout)
Output for each query line (top/getMin)
Your program must read from stdin and write the answer to stdout (no extra debug text).
5 push -2 push 0 getMin pop top
-2
| Test | Status | Details |
|---|
Ready — edit the code above and click Run or Submit.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
class Program
{
static int[] Ria(string line = null)
{
line ??= Console.ReadLine();
if (string.IsNullOrWhiteSpace(line)) return Array.Empty<int>();
return line.Trim().Split(new[] { ' ', ',', '\t' }, StringSplitOptions.RemoveEmptyEntries)
.Select(int.Parse).ToArray();
}
static string[] Rsa()
{
int n = int.Parse(Console.ReadLine());
var arr = new string[n];
for (int i = 0; i < n; i++) arr[i] = Console.ReadLine();
return arr;
}
static void W(params object[] parts) => Console.WriteLine(string.Join(" ", parts));
static void Wb(bool v) => Console.WriteLine(v ? "true" : "false");
static void Wi(int v) => Console.WriteLine(v);
static void Ws(string v) => Console.WriteLine(v);
static void Main()
{
int n = int.Parse(Console.ReadLine());
var st = new Stack<int>();
var mins = new Stack<int>();
for (int i = 0; i < n; i++) {
var parts = Console.ReadLine().Split(' ');
if (parts[0] == "push") {
int x = int.Parse(parts[1]);
st.Push(x);
mins.Push(mins.Count == 0 ? x : Math.Min(x, mins.Peek()));
} else if (parts[0] == "pop") { st.Pop(); mins.Pop(); }
else if (parts[0] == "top") Wi(st.Peek());
else if (parts[0] == "getMin") Wi(mins.Peek());
}
}
}Try solving on your own first, then reveal the official answer.
Pattern: Stack
Read from stdin, write to stdout. Classic interview problem #155.