1 million number of first 100

In the case of limited memory, the first 100 of the 1 million numbers are calculated.

Problem-solving ideas: The first thought is to divide 1 million numbers into 100 parts, one is 10,000, and then 10,000 to build a minimum heap to find the first 100, 100 is 10,000 so you can find the first 100;

The code is as follows:

#include <windows.h>

#include <vector>

#include <ctime>

#include <cstdlib>

#include <iostream>

using namespace Std;

const int n=10000;

const int k=100;

void Createarray (Vector<int>&array)

{

Srand (Time (0));

Array.reserve (N);

for (size_t i = 0; i < N; i++)

{

Array.push_back (rand ()% 10000);

}

for (size_t j = n-k; J < N; J + +)

{

ARRAY[J] = rand ()%N;

}

}

void Adjustdown (int* A, size_t size, int root)

{

int child = root * 2 + 1;

while (Child < size)

{

if (child + 1 <size && A[child + 1] < A[child])

{

++child;

}

if (A[child] < A[root])

{

Swap (A[child], a[root]);

root = child;

Child = 2 * root + 1;

}

Else

{

Break

}

}

}

void Gettop (Vector<int>&array)

{

int A[k] = {};

for (size_t i = 0; i < K; i++)

{

A[i] = Array[i];

}

for (int i = (K-2)/2; I >= 0; i--)

{

Adjustdown (A, K, i);

}

for (int j = K; J < N; J + +)

{

if (A[0]<array[j])

{

A[0] = Array[j];

Adjustdown (A, K, 0);

}

}

for (size_t i = 0; i < K; i++)

{

cout << A[i] << "";

}

cout << Endl;

}

void Test ()

{

vector<int>array;

Createarray (array);

Gettop (array);

}

This article is from the "Stream Wind" blog, please be sure to keep this source http://xiexiankun.blog.51cto.com/10785425/1775367

1 million number of first 100