Go: package main

// packed from [splaytree.go main.rmq.go splaytree_debug.go] with goone.

import (
	"bufio"
	"fmt"
	"io"
	"os"
	"strconv"
	"strings"
)

type SplayTreeNode struct {
	parent, left, right *SplayTreeNode

	size    int
	value   int
	minimum int
}

func newSplayTreeNode(v int) *SplayTreeNode {
	return &SplayTreeNode{value: v}
}

func (node *SplayTreeNode) rotate() {
	var pp, p, c *SplayTreeNode
	p = node.parent
	pp = p.parent
	if pp != nil && pp.left == p {
		pp.left = node
	}
	if pp != nil && pp.right == p {
		pp.right = node
	}
	node.parent = pp
	if p.left == node {
		c = node.right
		node.right = p
		p.left = c
	} else {
		c = node.left
		node.left = p
		p.right = c
	}
	p.parent = node
	if c != nil {
		c.parent = p
	}
	p.update()
	node.update()
}

func (node *SplayTreeNode) state() int {
	if node.parent == nil {
		return 0
	}
	if node.parent.left == node {
		return -1
	} else if node.parent.right == node {
		return 1
	}
	return 0
}

func (node *SplayTreeNode) splay() {
	for node.state() != 0 {
		if node.parent.state() == 0 {
			node.rotate()
			return
		}
		if node.state() == node.parent.state() {
			node.parent.rotate()
			node.rotate()
		} else {
			node.rotate()
			node.rotate()
		}
	}
}

func (node *SplayTreeNode) update() {
	node.size = 1
	node.minimum = node.value
	if node.left != nil {
		node.size += node.left.size
		node.minimum = min(node.minimum, node.left.minimum)
	}
	if node.right != nil {
		node.size += node.right.size
		node.minimum = min(node.minimum, node.right.minimum)
	}
}
func min(a, b int) int {
	if a < b {
		return a
	}
	return b
}

func (node *SplayTreeNode) Get(idx int) *SplayTreeNode {
	cur := node
	for true {
		lSize := 0
		if cur.left != nil {
			lSize = cur.left.size
		}
		if idx < lSize {
			cur = cur.left
		}
		if lSize == idx {
			cur.splay()
			return cur
		}
		if idx > lSize {
			cur = cur.right
			idx = idx - lSize - 1
		}
	}
	return nil
}

func mergeSplayNode(l, r *SplayTreeNode) (root *SplayTreeNode) {
	if l == nil {
		return r
	}
	if r == nil {
		return l
	}
	root = l.Get(l.size - 1)
	root.right = r
	r.parent = root
	root.update()
	return root
}

func (node *SplayTreeNode) Split(leftCount int) (left *SplayTreeNode, right *SplayTreeNode) {
	root := node.Get(leftCount)
	lRoot, rRoot := root.left, root

	rRoot.left = nil
	if lRoot != nil {
		lRoot.parent = nil
	}
	rRoot.update()
	return lRoot, rRoot
}

func splayTreeInsert(t *SplayTreeNode, idx int, node *SplayTreeNode) (root *SplayTreeNode) {
	l, r := t.Split(idx)
	return mergeSplayNode(
		mergeSplayNode(l, node),
		r,
	)
}

func removeSplayTree(t *SplayTreeNode, idx int) (root *SplayTreeNode, removed *SplayTreeNode) {
	target := t.Get(idx)
	l, r := target.left, target.right
	if l != nil {
		l.parent = nil
	}
	if r != nil {
		r.parent = nil
	}
	target.left = nil
	target.right = nil
	target.update()
	return mergeSplayNode(l, r), target
}

const (
	initialBufSize = 100000
	maxBufSize     = 1000000
)

var sc *bufio.Scanner

func initScanner(r io.Reader) *bufio.Scanner {
	buf := make([]byte, initialBufSize)

	sc := bufio.NewScanner(r)
	sc.Buffer(buf, maxBufSize)
	sc.Split(bufio.ScanWords)
	return sc
}

func main() {
	sc = initScanner(os.Stdin)
	resolve()
}

func resolve() {
	n := scanInt(sc)
	q := scanInt(sc)
	table := newDebugNodeSlice(200001)
	for i := 0; i < n; i++ {
		table.l[i].parent = &table.l[i+1]
		table.l[i+1].left = &table.l[i]
		table.l[i].update()
		table.l[i+1].update()
	}
	var root *SplayTreeNode = &table.l[n]
	for i := 0; i < n; i++ {
		table.l[i].value = scanInt(sc)
		table.l[i].update()
	}
	table.l[n].update()
	for i := 0; i < q; i++ {
		switch scanInt(sc) {
		case 0:
			root = shift(root, scanInt(sc), scanInt(sc))
		case 1:
			l := scanInt(sc)
			r := scanInt(sc)
			tmp, rRoot := root.Split(r + 1)
			lRoot, cRoot := tmp.Split(l)
			fmt.Println(cRoot.minimum)
			root = mergeSplayNode(mergeSplayNode(lRoot, cRoot), rRoot)
		case 2:
			root = root.Get(scanInt(sc))
			root.value = scanInt(sc)
			root.update()
		}
	}
}


C++: // AOJ 1508
#include<cstdio>
#include<ctime>
#include<algorithm>
#include<utility>
#define rep(i,a) for( int i = 0; i != (a); ++i )

template<class T>
struct treap
{
	struct node_t
	{
		T val, sum;
		node_t *lch, *rch;
		int pri, cnt;

		node_t( T v, int p )
		:	val( v ), pri( p ), cnt( 1 ), sum( v ), lch( NULL ), rch( NULL )
		{}
	};

	static const int INF = 1<<30;
	node_t *root;
	treap()
	:	root( NULL )
	{}

	int count( node_t *t )
	{
		return t ? t->cnt : 0;
	}
	
	T sum( node_t *t )
	{
		return t ? t->sum : INF;
	}

	int size()
	{
		return count( root );
	}

	node_t *update( node_t *t )
	{
		t->cnt = count( t->lch ) + count( t->rch ) + 1;
		t->sum = std::min( std::min( sum( t->lch ), sum( t->rch ) ), t->val );
	
		return t;
	}

	node_t *merge( node_t *l, node_t *r )
	{
		if( !l || !r )
			return l?l:r;

		if( l->pri > r->pri )
		{
			l->rch = merge( l->rch, r );
			return update(l);
		}
		else
		{
			r->lch = merge( l, r->lch );
			return update(r);
		}
	}

	std::pair<node_t *, node_t *> split( node_t *t, int k )
	{
		if( !t )
			return std::make_pair( (node_t *)NULL, (node_t *)NULL );
		
		if( k <= count( t->lch ) )
		{
			std::pair<node_t *, node_t *> s = split( t->lch, k );
			t->lch = s.second;
			return std::make_pair( s.first, update(t) );
		}
		else
		{
			std::pair<node_t *, node_t *> s = split( t->rch, k-count(t->lch)-1 );
			t->rch = s.first;
			return std::make_pair( update(t), s.second );
		}
	}

	node_t *insert( node_t *t, int k, T val, int pri )
	{
		std::pair<node_t *, node_t *> s = split( t, k );
		t = merge( s.first, new node_t( val, pri ) );
		t = merge( t, s.second );
		
		return update(t);
	}
	node_t *erase( node_t *t, int k )
	{
		std::pair<node_t *, node_t *> s1, s2;
		s2 = split( t, k+1 );
		s1 = split( s2.first, k );
		t = merge( s1.first, s2.second );
		
		return update(t);
	}
	node_t *find( node_t *t, int k )
	{
		int c = count( t->lch );
		if( k < c )
			return find( t->lch, k );
		else if( k == c )
			return t;
		else
			return find( t->rch, k-c-1 );
	}
	void insert( int k, T val )
	{
		root = insert( root, k, val, rand() );

		return;
	}
	void erase( int k )
	{
		root = erase( root, k );

		return;
	}
	node_t *find( int k )
	{
		return find( root, k );
	}

	void shift( int l, int r )
	{
		std::pair<node_t *, node_t *> a, b, c;
		c = split( root, r );
		b = split( c.first, r-1 );
		a = split( b.first, l );
		root = merge( a.first, b.second );
		root = merge( root, a.second );
		root = merge( root, c.second );

		return;
	}
	int query( int l, int r, node_t *t )
	{
		int sz = count(t);
		if( l >= sz || r <= 0 )
			return INF;
		if( l <= 0 && r >= sz )
			return sum(t);

		int c = count(t->lch), ret = std::min( query( l, r, t->lch ), query( l-c-1, r-c-1, t->rch ) );

		if( l <= c && c < r )
			ret = std::min( ret, t->val );

		return ret;
	}
};

int main()
{
	srand((unsigned)time(NULL));
	int n, q;
	treap<int> t;

	scanf( "%d%d", &n, &q );
	rep( i, n )
	{
		int a;
		scanf( "%d", &a );
		t.insert( i, a );
	}

	while( q-- )
	{
		int x, y, z;
		scanf( "%d%d%d", &x, &y, &z );
		if( !x )
			t.shift( y, z+1 );
		else if( x == 1 )
			printf( "%d\n", t.query( y, z+1, t.root ) );
		else if( x == 2 )
		{
			t.erase( y );
			t.insert( y, z );
		}
	}

	return 0;
}