I Hate It
Time Limit: 9000/3000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others)
Problem Description
A habit of comparison prevails in many schools. Teachers like to ask, from so-and-so to so-and-so, what is the highest score.
This makes many students very disgusted.
Whether you like it or not, what you need to do now is to write a program to simulate the teacher's inquiry according to the teacher's requirements. Of course, teachers sometimes need to update a student's grades.
This makes many students very disgusted.
Whether you like it or not, what you need to do now is to write a program to simulate the teacher's inquiry according to the teacher's requirements. Of course, teachers sometimes need to update a student's grades.
Input
This topic contains a number of groups of tests, please process to the end of the file.
In the first line of each test, there are two positive integers, N and M (0 < N <= 200000, 0 < M < 5000), representing the number of students and the number of operations, respectively.
Student ID numbers range from 1 to N, respectively.
The second line contains N integers representing the initial grades of the N students, and the number i represents the grades of the students whose ID is i.
Then there's line M. Each line has a character C (only'Q'or'U') and two positive integers A and B.
When C is'Q', it means that this is a query operation. It asks the students whose ID is from A to B (including A,B), what is the highest score.
When C is'U', it means that this is an update operation, requiring that the grade of the student whose ID is A be changed to B.
In the first line of each test, there are two positive integers, N and M (0 < N <= 200000, 0 < M < 5000), representing the number of students and the number of operations, respectively.
Student ID numbers range from 1 to N, respectively.
The second line contains N integers representing the initial grades of the N students, and the number i represents the grades of the students whose ID is i.
Then there's line M. Each line has a character C (only'Q'or'U') and two positive integers A and B.
When C is'Q', it means that this is a query operation. It asks the students whose ID is from A to B (including A,B), what is the highest score.
When C is'U', it means that this is an update operation, requiring that the grade of the student whose ID is A be changed to B.
Output
For each query operation, output the highest score in one line.
Sample Input
5 6 1 2 3 4 5 Q 1 5 U 3 6 Q 3 4 Q 4 5 U 2 9 Q 1 5
Sample Output
5 6 5 9HintHuge input,the C function scanf() will work better than cin
# include <cstdio>
# include <cstring>
# include <cmath>
# include <algorithm>
# define MAXN 2000005
using namespace std;
int n, m;
int arr[MAXN * 2];
int max(int a, int b) //You can't use macro definitions to define max, which can lead to serious timeouts
{
return a > b ? a : b;
}
void Build(int node, int nstart, int nend)
{
if (nstart == nend)
{
scanf("%d", &arr[node]);
return;
}
int mid = (nstart + nend) >> 1;
Build(node << 1, nstart, mid);
Build((node << 1) | 1, mid + 1, nend);
arr[node] = max(arr[node << 1], arr[(node << 1) | 1]);
}
void Update(int node, int nstart, int nend, int pos, int updatenum)
{
if (nstart == nend)
{
arr[node] = updatenum;
return;
}
int mid = (nstart + nend) >> 1;
if (pos > mid)
{
Update((node << 1) | 1, mid + 1, nend, pos, updatenum);
}
else
{
Update(node << 1, nstart, mid, pos, updatenum);
}
arr[node] = max(arr[node << 1], arr[(node << 1) | 1]);
}
int Query(int node, int nstart, int nend, int qstart, int qend)
{
if (qstart <= nstart && qend >= nend)
{
return arr[node];
}
int mid = (nstart + nend) >> 1;
int ret = 0;
if (qstart <= mid)
{
ret = max(ret, Query(node << 1, nstart, mid, qstart, qend));
}
if (qend > mid)
{
ret = max(ret, Query((node << 1) | 1, mid + 1, nend, qstart, qend));
}
return ret;
}
int main(void)
{
int i;
char str;
int a, b;
while (~scanf("%d %d", &n, &m))
{
//memset(arr, 0, sizeof(arr));
Build(1, 1, n);
for (i = 0; i < m; i++)
{
scanf("%*c%c%d%d", &str, &a, &b);
if ('U' == str)
{
Update(1, 1, n, a, b);
//printf("%c\n", str[0]);
}
else
{
printf("%d\n", Query(1, 1, n, a, b));
}
}
}
return 0;
}