HDU 1425 Sort (heap sort/fast row)

Transmission Door

Description

give you n integers, please output the number of the first m large in order from large to small.

Input

each set of test data has two lines, the first row has two number n,m (0<n,m<1000000), the second row contains n each are different, and are in the interval [ -500000,500000] integer.

Output

outputs the number of previous m large for each set of test data in order from large to small.

Sample Input

3-35 92 213-644

Sample Output

213 92 3

1. Use the built-in sort function

#include <iostream> #include <algorithm> #include <cstdio>using namespace Std;int ans[1000001];int Main () {    int n,m;    while (scanf ("%d%d", &n,&m)! = EOF)    {        for (int i = 0;i < n;i++)        {            scanf ("%d", &ans[i]);        }        Sort (Ans,ans + N);        printf ("%d", ans[n-1]);        for (int i = n-2;m > 1;m--, i--)        {            printf ("%d", ans[i]);        }         printf ("\ n");    }    

2. Use the built-in priority queue

#include <iostream> #include <queue> #include <cstdio>using namespace Std;int main () {    int n,m;    while (~SCANF ("%d%d", &n,&m))    {        priority_queue<int>que;        BOOL first = true;        int tmp;        while (n--)        {            scanf ("%d", &tmp);            Que.push (TMP);        }         while (m--)        {            first?printf ("%d", Que.top ()):p rintf ("%d", que.top ());            Que.pop ();            First = false;        }        printf ("\ n");    }    return 0;}

3. Using internal heap functions

#include <cstdio> #include <algorithm>using namespace std;static int A[1000000];int main () {    int i,n,m;< C1/>while (EOF! = scanf ("%d%d", &n,&m))    {for        (i=0;i<n;i++)            scanf ("%d", &a[i]);        Make_heap (a,a+n);        printf ("%d", a[0]);        for (i=1;i<m;i++)        {            pop_heap (a,a+n-i+1);            printf ("%d", a[0]);        }        printf ("\ n");    }    return 0;}

4, handwritten heap sorting

#include <stdio.h> #include <string.h>const int maxn = 1000005;int Heap[maxn],sz = 0;void push (int x) {    int i = sz++;    while (i > 0)    {        int p = (i-1)/2;        if (Heap[p] >= x) break    ;        Heap[i] = heap[p];        i = P;    }    Heap[i] = x;} int pop () {    int ret = heap[0];    int x = Heap[--sz];    int i = 0;    while (I*2+1<sz)    {        int a = I*2+1,b = i*2+2;        if (b < sz && heap[b]>heap[a])    a = B;        if (Heap[a] <= x) break    ;        Heap[i] = Heap[a];        i = A;    }    Heap[i] = x;    return ret;} int main () {    int n,m,tmp;    while (~SCANF ("%d%d", &n,&m))    {        sz = 0;        memset (heap,0,sizeof (heap));        for (int i = 0;i < n;i++)    scanf ("%d", &tmp), push (TMP);        for (int i = 1;i < m;i++)    printf ("%d", pop ());        printf ("%d\n", Pop ());    }    return 0;}

　　

HDU 1425 Sort (heap sort/quick Row)