RACETIME - Race Against Time
As another one of their crazy antics, the N (1 ≤ N ≤ 100,000) cows want Farmer John to race against the clock to answer some of their pressing questions.
The cows are lined up in a row from 1 to N, and each one is holding a sign representing a number, Ai (1 ≤ Ai ≤ 1,000,000,000). The cows need FJ to perform Q (1 ≤ Q ≤ 50,000) operations, which can be either of the following:
- Modify cow i's number to X (1 ≤ X ≤ 1,000,000,000). This will be represented in the input as a line containing the letter M followed by the space-separated numbers i and X.
- Count how many cows in the range [P, Q] (1 ≤ P ≤ Q ≤ N) have Ai ≤ X (0 ≤ X ≤ 1,000,000,000). This will be represented in the input as a line containing the letter C followed by the space-separated numbers P, Q, and X.
Of course, FJ would like your help.
Input
The first line gives the integers N and Q, and the next N lines give the initial values of Ai. Finally, the next Q lines each contain a query of the form "M i X" or "C P Q X".
Output
Print the answer to each 'C' query, one per line.
Example
Input: 4 6 3 4 1 7 C 2 4 4 M 4 1 C 2 4 4 C 1 4 5 M 2 10 C 1 3 9 Output: 2 3 4 2
FJ has 4 cows, whose initial numbers are 3, 4, 1, and 7. The cows then give him 6 operations; the first asks him to count the how many of the last three cows have a number at most 4, the second asks him to change the fourth cow's number to 1, etc.
===================================editorial=====================================
divide the array in sqrt part and each part contain a sorted vector , now iterate block wise , if a block completely inside the range than count using b'search ( since content of block is sorted) else if a block is partially in the range than iterate , in that block,,
for update , replace and sort the vector of the block ....
================================code===============================================#include<bits/stdc++.h>
using namespace std;
vector<int> block[1000];
int arr[1000000];
int main()
{
int n,q;
scanf("%d %d",&n,&q);
int sq=317;
int b_size=317;
if(sqrt(n)*sqrt(n)!=n)
{
sq++;
b_size++;
}
for(int i=0;i<n;i++)
{
int a;
scanf("%d",&a);
arr[i]=a;
block[i/b_size].push_back(a);
}
for(int i=0;i<sq;i++)
{
sort(block[i].begin(),block[i].end());
}
for(int i=0;i<q;i++)
{
char type;
cin>>type;
if(type=='C')
{
int l,r,val;
scanf("%d %d %d",&l,&r,&val);
int ans=0;
l--;
r--;
for(int i=0;i<sq;i++)
{
int bs=i*b_size;
int be=bs+b_size-1;
if(l<=bs && r>=be)
{
int count=upper_bound(block[i].begin(),block[i].end(),val)-block[i].begin();
ans+=count;
}
else
{
for( int j = max(bs,l) ; j <= min(be,r);j++ ) // if range have some portion in this block
ans += (arr[j]<=val) ;
}
}
printf("%d\n",ans);
}
else
{
int idx;int val;
scanf("%d %d",&idx,&val);
idx--;
int bnum=idx/b_size;
int remove=arr[idx];
// int f=0;
for(int i=0;i<b_size;i++)
{
if(block[bnum][i]==remove)
{
block[bnum][i]=val;
arr[idx]=val;
break;
}
}
sort(block[bnum].begin(),block[bnum].end());
}
}
}
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