1. In certain problems we can use an array of integers to solve the problem. But those can also be solved by using array of vectors. On which factors should I decide whether to use plain array of integers or array of vectors? If vectors, then what are the advantages?

2. Can function write in C++ return more than one values?

3. Can anyone tell me whats exact stack limit for c++ and can we increase it in some way from code?

4. Is true that vector increasing size by 2,4,8,16...? If it is are vector still increasing after will write resize?

5. What is complexity of memset(C++)? Is that faster then BF method?

6. In what type of data do you keep binary tree at your C++ program? And what is the best way to do it?

7. Is there any difference between char, string, vector in time complexity of processing(input, output...)?

8. I read about function nth_element on STL. Can anyone help me to implement it because how I can understand it's cool function in linear time complexity.

9. What is the difference between I write double pi = 3.14159; or #define pi 3.14159?

10. Is there any link on the Internet on page or book title like: "Hasing for dummies "

First I want you to read the task and try to solve it in linear time complexity, and minimum memorize complexity.

Lonely Integer
There are N integers in an array A. All but one integer occurs in pairs. Your task is to find out the number that occurs only once.

Input Format

The first line of the input contains an integer N indicating number of integers in the array A. The next line contains N integers each separated by a single space. Constraints 1 <= N < 100 N % 2 = 1 ( N is an odd number ) 0 <= A[i] <= 100, ∀ i ∈ [1, N]

Output Format

Output S, the number that occurs only once.
Sample Input
3
1 1 2
Sample Output
2

If you don't have any idea I will write a code.

#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;


int main() {
 	int N;
	cin >> N;
	int tmp, result = 0;
	for (int i = 0; i < N; i++) {
		cin >> tmp;
		result ^= tmp;
	}
	cout << result;
    return 0;
}

Cool trick using only xor operation, but I can't prove why that work. Can anyone prove it?

The number is the "law" if it consists only of digits 3 and 5 or if it is divisible by the number that is law.
For example, the numbers 3, 53, 66, 106 are "law" numbers, and 16, 34 and 56 did not.
How many there are "Law" numbers greater than or equal to A and smaller than or equal to B?

input
The first line contains two integers A and B (1 ≤ A ≤ B ≤ 10^9).
output
The first and only line of output as the "law" of numbers in the interval [a, b].

Examples:

entrance
1 10
output
5

entrance
171 822
output
315

Any idea how to solve it?

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The given is N non-negative numbers, select exactly K who provide minimal result of OR operation (binary OR operation).

Input The first line contains an integer N (1 ≤ K ≤ N ≤ 50). The next line contains N integers not exceeding 1000 000 000

Output

Print result of OR operation selected K numbers.

Examples:

entrance

2 2
1 3

output

3

entrance

6 3
5 2 4 1 7 5

output

5

Any ideas how to solve it?

Can anyone help with this task.

Given a sequence of N different integers. Operations allowed members of the series are:

• Move to the beginning of the sequence

• Move to the end of the sequence

Print the smallest number of necessary operations to a default set of ascending sorted.

For example:

Input

4

3 4 2 1

Output

2

Thank you.

Can anyone please help me with my solution. Codeforces evaluator say that is crashed, but I can normaly test it.

Link: http://mirror.codeforces.com/contest/433/submission/6708852

We have a sequence. What is the smallest number should be removed to sequence be a growing array?

Example: 5 1 2 4 3 6 4 6

If left sequence 1 2 4 6 then we kicked four numbers.

And if you leave the series 1 2 3 4 6 then we threw three the number of which is better than four.

So answer is 3. Can anyone have any idea how to solve by DP? Sorry for bad English.

Can you write a faster way to check is number N prime?

http://collabedit.com/fj2dc

Write in URL.

Thank you

Can anyone help me and write down miller rabin test example in c++? Thank you. ;)