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 Rust (judge verdict: Accepted)

use std::io::Read;

mod segment_tree {
    pub struct SegmentTree<T, F> {
        size: usize,
        data: Vec<T>,
        identity: T,
        operation: F,
    }

    impl<T: Clone + Copy, F: Fn(T, T) -> T> SegmentTree<T, F> {
        pub fn new(n: usize, id: T, op: F) -> SegmentTree<T, F> {
            let mut size = 1;
            while size < n {
                size <<= 1;
            }
            SegmentTree {
                size: size,
                data: vec![id; size * 2 - 1],
                identity: id,
                operation: op,
            }
        }

        pub fn update(&mut self, mut i: usize, x: T) {
            i += self.size - 1;
            self.data[i] = x;
            while i > 0 {
                i = (i - 1) / 2;
                self.data[i] = (self.operation)(self.data[i * 2 + 1], self.data[i * 2 + 2]);
            }
        }

        pub fn query(&self, a: usize, b: usize) -> T {
            return self._query(a, b, 0, 0, self.size);
        }

        fn _query(&self, a: usize, b: usize, i: usize, l: usize, r: usize) -> T {
            if b <= l || r <= a {
                return self.identity;
            }
            if a <= l && r <= b {
                return self.data[i];
            }
            let v1 = self._query(a, b, i * 2 + 1, l, (l + r) / 2);
            let v2 = self._query(a, b, i * 2 + 2, (l + r) / 2, r);
            return (self.operation)(v1, v2);
        }
    }
}

fn main() {
    let mut s: String = String::new();
    std::io::stdin().read_to_string(&mut s).ok();
    let mut itr = s.trim().split_whitespace();
    let n: usize = itr.next().unwrap().parse().unwrap();
    let q: usize = itr.next().unwrap().parse().unwrap();
    let mut st = segment_tree::SegmentTree::new(n, (1u64 << 31) - 1, std::cmp::min);
    for _ in 0..q {
        let t: usize = itr.next().unwrap().parse().unwrap();
        let l: usize = itr.next().unwrap().parse().unwrap();
        let r: usize = itr.next().unwrap().parse().unwrap();
        if t == 0 {
            st.update(l, r as u64);
        } else {
            println!("{}", st.query(l, r + 1));
        }
    }
}