CodeForces 438D

At the children’s day, the child came to Picks’s house, and messed his house up. Picks was angry at him. A lot of important things were lost, in particular the favorite sequence of Picks.

Fortunately, Picks remembers how to repair the sequence. Initially he should create an integer array a[1], a[2], …, a[n]. Then he should perform a sequence of m operations. An operation can be one of the following:

Print operation l, r. Picks should write down the value of sum .
Modulo operation l, r, x. Picks should perform assignment a[i] = a[i] mod x for each i (l ≤ i ≤ r).
Set operation k, x. Picks should set the value of a[k] to x (in other words perform an assignment a[k] = x).
Can you help Picks to perform the whole sequence of operations?

Input

The first line of input contains two integer: n, m (1 ≤ n, m ≤ 105). The second line contains n integers, separated by space: a[1], a[2], …, a[n] (1 ≤ a[i] ≤ 109) — initial value of array elements.

Each of the next m lines begins with a number type .

If type = 1, there will be two integers more in the line: l, r (1 ≤ l ≤ r ≤ n), which correspond the operation 1.
If type = 2, there will be three integers more in the line: l, r, x (1 ≤ l ≤ r ≤ n; 1 ≤ x ≤ 109), which correspond the operation 2.
If type = 3, there will be two integers more in the line: k, x (1 ≤ k ≤ n; 1 ≤ x ≤ 109), which correspond the operation 3.

Output

For each operation 1, please print a line containing the answer. Notice that the answer may exceed the 32-bit integer.

Examples Input

5 5
1 2 3 4 5
2 3 5 4
3 3 5
1 2 5
2 1 3 3
1 1 3

Output

8
5

Input

10 10
6 9 6 7 6 1 10 10 9 5
1 3 9
2 7 10 9
2 5 10 8
1 4 7
3 3 7
2 7 9 9
1 2 4
1 6 6
1 5 9
3 1 10

Output

49
15
23
1
9

Note

Consider the first testcase:

At first, a = {1, 2, 3, 4, 5}.
After operation 1, a = {1, 2, 3, 0, 1}.
After operation 2, a = {1, 2, 5, 0, 1}.
At operation 3, 2 + 5 + 0 + 1 = 8.
After operation 4, a = {1, 2, 2, 0, 1}.
At operation 5, 1 + 2 + 2 = 5.

给一个序列
支持3种操作
1 u v 对于所有i u<=i<=v,输出a[i]的和
2 u v t 对于所有i u<=i<=v a[i]=a[i]%t
3 u v 表示a[u]=v(将v赋值给a[u])
n,q<=1e5 a[i],t,v<=1e9

Input
5 5
1 2 3 4 5
2 3 5 4
3 3 5
1 2 5
2 1 3 3
1 1 3

Output
8
5

提示
对于a%=b,如果a>=b,那么a至少除以2,也就是一个数最多减小log次

题目大意:
输入n和m,表示有n个数和m个询问,对于每个询问有三种操作:

  • u v 对于所有i u<=i<=v,输出a[i]的和
  • u v t 对于所有i u<=i<=v a[i]=a[i]%t
  • u v 表示a[u]=v(将v赋值给a[u])

解题思路:
这道题是线段树的基础题,对于这三种操作,单点替换和区间求和直接套用模板就可以,对于区间内每一个点需要剪枝,不剪枝一定会TLE,我们需要建两个树,一个存放sum的值,另一个用于存放每个节点的max,取模时我们判断一下该节点的子节点最大值是不是小于要取模的数,如果小于则直接不用判断。AC代码:

#include <cstdio>
#include <iostream>
#include <algorithm>
using namespace std;
using ll = long long;
const ll _max=1e5+50;
ll arr[_max],tree[4*_max],treem[4*_max];
int main()
{
	void build_tree(int,int,int);
	void update(int,int,int,int,int);
	ll query(int,int,int,int,int);
	void mod1(int,int,int,int,int,int);
	int n,m;
	scanf("%d%d",&n,&m);
	for ( int i = 0; i < n; i++)
	  cin>>arr[i];
	build_tree(0,0,n-1);
	while(m--)
	{
		int k,a,b,c;
		scanf("%d",&k);
		if(k==1)
		{
			scanf("%d%d",&a,&b);
			ll sum=query(0,0,n-1,a-1,b-1);
			printf("%lld
",sum);
		}
		else if(k==2)
		{
			scanf("%d%d%d",&a,&b,&c);
			mod1(0,0,n-1,a-1,b-1,c);
		}
		else
		{
			scanf("%d%d",&a,&b);
			update(0,0,n-1,a-1,b);
		}
	}
 	//system("pause");
	return 0;
}
void build_tree(int node ,int start ,int end)
{
	if(start==end)
	{
		tree[node]=arr[start];
		treem[node]=arr[start];
		return;
	}
	int left_node = node*2+1;
	int right_node = node*2+2;
	int mid=(start+end)>>1;
	build_tree(left_node,start,mid);
	build_tree(right_node,mid+1,end);
	tree[node]=tree[left_node]+tree[right_node];
	treem[node]=max(treem[left_node],treem[right_node]);
}
void update(int node, int start, int end, int idx, int val)
{
	if(start==end)
	{
		tree[node]=val;
		treem[node]=val;
		return;
	}
	int left_node = node*2+1;
	int right_node = node*2+2;
	int mid=(start+end)>>1;
	if(idx>=start&&idx<=mid)
		update(left_node,start,mid,idx,val);
	else
		update(right_node,mid+1,end,idx,val);
	tree[node]=tree[left_node]+tree[right_node];
	treem[node]=max(treem[left_node],treem[right_node]);
}
ll query(int node, int start, int end, int l, int r)
{
    if(l<=start&&r>=end)
      return tree[node];   
    int left_node=node*2+1;
    int right_node=node*2+2;
    int mid=(start+end)>>1;
	ll suml,sumr;
	suml=sumr=0;
	if(l<=mid)
      suml=query(left_node,start,mid,l,r);
    if(r>mid)
	  sumr=query(right_node,mid+1,end,l,r);
    return suml+sumr;
}
void mod1(int node, int start, int end, int l, int r,int mod)
{
	if(treem[node]<mod)
	  return;//这里注意一下,用子节点的最大值去比较
    else if(start==end)
    {
		tree[node]=tree[node]%mod;
		treem[node]=treem[node]%mod;
		return;
	}
    else 
    {
        int left_node=node*2+1;
        int right_node=node*2+2;
        int mid=(start+end)>>1;
		if(l<=mid)
          mod1(left_node,start,mid,l,r,mod);
        if(r>mid)
		  mod1(right_node,mid+1,end,l,r,mod);
        tree[node]=tree[left_node]+tree[right_node];
		treem[node]=max(treem[left_node],treem[right_node]);
    }
}
原文地址:https://www.cnblogs.com/Hayasaka/p/14294279.html