Problem:
Range Minimum Query (RMQ)

Write a program which manipulates a sequence A = {a0, a1, . . . , an-1} with the following operations:

find(s, t): report the minimum element in as, as+1, . . . ,at.

update(i, x): change ai to x.

Note that the initial values of ai (i = 0, 1, . . . , n−1) are 231-1.

Input

n q
com0 x0 y0
com1 x1 y1
...
comq−1 xq−1 yq−1

In the first line, n (the number of elements in A) and q (the number of queries) are given. Then, q queries are given where com represents the type of queries. '0' denotes update(xi, yi) and '1' denotes find(xi, yi).

Output

For each find operation, print the minimum element.

Constraints

1 ≤ n ≤ 100000

1 ≤ q ≤ 100000

If comi is 0, then 0 ≤ xi < n, 0 ≤ yi < 231-1.

If comi is 1, then 0 ≤ xi < n, 0 ≤ yi < n.

Sample Input 1

3 5
0 0 1
0 1 2
0 2 3
1 0 2
1 1 2

Sample Output 1

1
2

Sample Input 2

1 3
1 0 0
0 0 5
1 0 0

Sample Output 2

2147483647
5

Solution in C# (judge verdict: Wrong Answer)

using System;
using System.Linq;

namespace ACTest
{
    class AOJDSL2A
    {
        static void Main(string[] args)
        {
            string[] input = Console.ReadLine().Split(' ');
            int num = int.Parse(input[0]);
            int query = int.Parse(input[1]);
            int[] com = new int[query];
            int[] x = new int[query];
            int[] y = new int[query];
            for (int i = 0; i < query; i++)
            {
                input = Console.ReadLine().Split(' ');
                com[i] = int.Parse(input[0]);
                x[i] = int.Parse(input[1]);
                y[i] = int.Parse(input[2]);
            }
            // make set
            int tree = 1;
            while (tree < num+1)
            {
                tree *= 2;
            }
            int[] dat = new int[2 * tree - 1];
            dat = Enumerable.Repeat<int>(2147483647, 2 * tree - 1).ToArray();
            for (int i = 0; i < query; i++)
            {
                if (com[i] == 0)
                {
                    update(tree, x[i], y[i], dat);
                }
                else if (com[i] == 1)
                {
                    Console.WriteLine(findQuery(x[i], y[i], 0, 0, num+1, dat));
                }
            }
            //while (true) ;

        }
        /// <summary>
        /// ?????¨??? com0
        /// </summary>
        /// <param name="n">?????????????????°num????????§??????????°????2????????????</param>
        /// <param name="k">k?????????</param>
        /// <param name="a">a????????????</param>
        /// <param name="dat">?????¨2?????¨</param>
        static void update(int n, int k, int a, int[] dat)
        {
            k += n - 1;
            dat[k] = a;
            while (k > 0)
            {
                k = (k - 1) / 2;
                dat[k] = Math.Min(dat[2 * k + 1], dat[2 * k + 2]);
            }
        }
        static int findQuery(int a, int b, int k, int l, int r, int[] dat)
        {
            if (r <= a || b <= l)
            {
                return 2147483647;
            }
            if (a <= l && r <= b)
            {
                return dat[k];
            }
            else
            {
                int vl = findQuery(a, b, 2 * k + 1, l, (l + r) / 2, dat);
                int vr = findQuery(a, b, 2 * k + 2, (l + r) / 2, r, dat);
                return Math.Min(vl, vr);
            }

        }
    }
}