#[derive(Debug, Clone)] struct SegmentTree { n: usize, orgn: usize, unit: T, mem: Vec, operator: F } impl SegmentTree where T: std::fmt::Debug + Clone, F: Fn(&T, &T) -> T { fn new(n: usize, unit: T, operator: F) -> Self { let mut size = 1usize; while size < n { size *= 2; } Self { n: size, orgn: n, unit: unit.clone(), mem: vec![unit.clone().to_owned(); size*2-1], operator: operator, } } fn find_closed(&self, l: usize, r: usize) -> T { self.find(l, r+1) } fn find(&self, l: usize, r: usize) -> T { self._find(l, r, 0, 0, self.n) } fn set(&mut self, pos: usize, val: T) { let mut pos = pos + self.n - 1; self.mem[pos] = val; while pos > 0 { pos = self._parent(pos); self.mem[pos] = (self.operator)(&self.mem[self._left(pos)], &self.mem[self._right(pos)]).clone().to_owned(); } } fn get(&mut self, pos: usize) -> &T { &self.mem[pos + self.n - 1] } fn _find(&self, a: usize, b: usize, nodenum: usize, l: usize, r: usize) -> T { if r <= a || b <= l { return self.unit.clone(); } else if a <= l && r <= b { return self.mem[nodenum].clone(); } let left = self._find(a, b, self._left(nodenum), l, (l+r)/2); let right = self._find(a, b, self._right(nodenum), (l+r)/2, r); (self.operator)(&left, &right) } fn _left(&self, k: usize) -> usize { 2*k+1 } fn _right(&self, k: usize) -> usize { 2*k+2 } fn _parent(&self, k: usize) -> usize { (k-1)/2 } } fn main() { let mut nq = String::new(); std::io::stdin().read_line(&mut nq).ok(); let nq: Vec = nq.trim().split_whitespace().map(|s| s.parse().unwrap()).collect(); let n = nq[0]; let q = nq[1]; let mut s = String::new(); std::io::stdin().read_line(&mut s).ok(); let s = s.trim().chars().collect::>(); let queries = (0..q).map(|_| { let mut temp = String::new(); std::io::stdin().read_line(&mut temp).ok(); let temp: Vec = temp.trim().split_whitespace().map(|s| s.parse().unwrap()).collect(); (temp[0]-1, temp[1]-1, temp[2]-1) }) .collect::>(); let operator = |x: &Vec, y: &Vec| { let n = x.len(); let m = y.len(); let mut ret = Vec::with_capacity(n+m); let mut xidx = 0usize; let mut yidx = 0usize; while xidx < n && yidx < m { if x[xidx] > y[yidx] { ret.push(y[yidx]); yidx += 1; } else { ret.push(x[xidx]); xidx += 1; } } while xidx < n { ret.push(x[xidx]); xidx += 1; } while yidx < m { ret.push(y[yidx]); yidx += 1; } ret }; let mut segtree = SegmentTree::new(n, vec![], operator); for i in 0..n { segtree.set(i, vec![s[i]]); } for &(l, r, x) in queries.iter() { println!("{}", segtree.find_closed(l, r)[x]); } }