Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"sort"
	"strconv"
)

func main() {
	mountHeightList := make([]int64, 10)
	scanner := bufio.NewScanner(os.Stdin)
	for i := 0; i < 10; i++ {
		scanner.Scan()
		mountHeightList[i], _ = strconv.ParseInt(scanner.Text(), 10, 64)
	}

	sort.Slice(mountHeightList, func(i, j int) bool { return mountHeightList[i] > mountHeightList[j] })

	for i := 0; i < 3; i++ {
		fmt.Printf("%d\n", mountHeightList[i])
	}
}

C++: /*{{{*/
#include <algorithm>
#include <cassert>
#include <cctype>
#include <climits>
#include <cmath>
#include <complex>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <iostream>
#include <iterator>
#include <list>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <sys/time.h>
#include <vector>
using namespace std;

#define INF (1e9)
static const double PI = acos(-1.0);
static const double EPS = 1e-10;

typedef long long int LL;
typedef unsigned long long int ULL;
typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<double> VD;
typedef vector<VD> VVD;
typedef vector<bool> VB;
typedef vector<VB> VVB;
typedef vector<char> VC;
typedef vector<VC> VVC;
typedef vector<string> VS;
typedef vector<VS> VVS;
typedef pair<int, int> PII;

#define FOR(i, b, e) for (typeof(e) i = (b); i != (e); i < (e)? ++i : --i)
#define REP(i, n) FOR(i, 0, n)

#define IFC(c) if(c) continue;
#define IFB(c) if(c) break;
#define IFR(c, r) if(c) return r;

#define OPOVER(_op, _type) inline bool operator _op (const _type &t) const

#define ARRSIZE(a) ( sizeof(a) / sizeof(a[0]) )
#define ZERO(a, v) ( assert(v == 0 || v == -1), memset(a, v, sizeof(a)) )

#define F first
#define S second
#define MP(a, b) make_pair(a, b)

#define SIZE(a) ((LL)a.size())
#define PB(e) push_back(e)
#define SORT(v) sort((v).begin(), (v).end())
#define RSORT(v) sort((v).rbegin(), (v).rend())

#define ALL(a) (a).begin(), (a).end()
#define RALL(a) (a).rbegin(), (a).rend()
#define EACH(c,it) for(__typeof((c).begin()) it=(c).begin(); it!=(c).end(); ++it)
#define EXIST(s,e) ((s).find(e)!=(s).end())

#define BIT(n) (assert(n < 64), (1ULL << (n)))
#define BITOF(n, m) (assert(m < 64), ((ULL)(n) >> (m) & 1))

#define RANGE(a, b, c) ((a) <= (b) && (b) <= (c))

#define PQ priority_queue
#define SC static_cast

#define dprt(fmt, ...) if (opt_debug) fprintf(stderr, fmt, ##__VA_ARGS__)
#define darr(a) if (opt_debug) copy( (a), (a) + arrsz(a), ostream_iterator<int>(cerr, " ") ); cerr << endl
#define darr_range(a, f, t) if (opt_debug) copy( (a) + (f), (a) + (t), ostream_iterator<int>(cerr, " ") ); cerr << endl
#define dvec(v) if (opt_debug) copy( ALL(v), ostream_iterator<int>(cerr, " ") ); cerr << endl
#define darr2(a, n, m) if (opt_debug) FOR(i, 0, (n)){ darr_range( (a)[i], 0, (m) ); }
#define dvec2(v) if (opt_debug) FOR(i, 0, SZ(v)){ dvec( (v)[i] ); }
#define WAIT() if (opt_debug) { string _wait_; cerr << "(hit return to continue)" << endl; getline(cin, _wait_); }
#define dump(x) if (opt_debug) cerr << " [L" << __LINE__ << "] " << #x << " = " << (x) << endl;
#define dumpf() if (opt_debug) cerr << __PRETTY_FUNCTION__ << endl;
#define dumpv(x) if (opt_debug) cerr << " [L:" << __LINE__ << "] " << #x << " = "; REP(q, (x).size()) cerr << (x)[q] << " "; cerr << endl;
#define where() if (opt_debug) cerr << __FILE__ << ": " << __PRETTY_FUNCTION__ << " [L: " << __LINE__ << "]" << endl;
#define show_bits(b, s) if(opt_debug) { REP(i, s) { cerr << BITOF(b, s-1-i); if(i%4 == 3) cerr << ' '; } cerr << endl; }

/* Inline functions */
inline int onbits_count(ULL b) { int c = 0; while(b != 0) { c += (b & 1); b >>= 1; } return c; }
inline int bits_count(ULL b) { int c = 0; while(b != 0) { ++c; b >>= 1; } return c; }
inline int toInt(string s) { int v; istringstream sin(s);sin>>v;return v; }
template<class T> inline string toString(T x) { ostringstream sout;sout<<x;return sout.str(); }
inline double now(){ struct timeval tv; gettimeofday(&tv, NULL); return (static_cast<double>(tv.tv_sec) + static_cast<double>(tv.tv_usec) * 1e-6); }
inline VS split(string s, char delimiter) { VS v; string t; REP(i, s.length()) { if(s[i] == delimiter) v.PB(t), t = ""; else t += s[i]; } v.PB(t); return v; }

/* Tweaks */
template<typename T1, typename T2> ostream& operator<<(ostream& s, const pair<T1, T2>& d) {return s << "(" << d.first << ", " << d.second << ")";}

/* Frequent stuffs */
// int n_dir = 4;
// int dx[] = {0, 1, 0, -1}, dy[] = {-1, 0, 1, 0}; [> CSS order <]
// enum direction {
	// UP, RIGHT, DOWN, LEFT
// };
// int n_dir = 8;
// int dx[] = {0, 1, 1, 1, 0, -1, -1, -1}, dy[] = {-1, -1, 0, 1, 1, 1, 0, -1};
// enum direction {
	// UP, UPRIGHT, RIGHT, DOWNRIGHT, DOWN, DOWNLEFT, LEFT, UPLEFT
// };
// #define FORDIR(d) REP (d, n_dir)

typedef complex<int> P;
#define Y real()
#define X imag()
P dyx[4] = { P(-1, 0), P(0, 1), P(1, 0), P(0, -1) };
// P dyx[8] = { P(-1, 0), P(0, 1), P(1, 0), P(0, -1), P(-1, 1), P(1, 1), P(1, -1), P(-1, -1) };

int g_height, g_width;
bool in_field(P p) {
	return (0 <= p.Y && p.Y < g_height) && (0 <= p.X && p.X < g_width);
}

/*}}}*/
bool opt_debug = false;

int main(int argc, char** argv) {
	std::ios_base::sync_with_stdio(false);
	// set options {{{
	int __c;
	while ( (__c = getopt(argc, argv, "d")) != -1 ) {
		switch (__c) {
			case 'd':
				opt_debug = true;
				break;
			default:
				abort();
		}
	}
	// }}}

	VI heights;
	REP (_, 10) {
		int h; cin >> h;
		heights.PB(h);
	}
	RSORT(heights);
	REP (i, 3) {
		cout << heights[i] << endl;
	}
}

// vim: foldmethod=marker

C++: #include<stdio.h>
#define ARRAY_SIZE 10
#define MAX_VALUE 10000
#define MIN_VALUE 0

int searchMax();
int *heightList;

int main(void){
  heightList = new int[ARRAY_SIZE];

  for(int i = 0;i < ARRAY_SIZE;i++){
    scanf("%d",&heightList[i]);
  }
  for(int i = 0;i < 3;i++){
    printf("%d\n",searchMax());
  }

  delete(heightList);

  return 0;
}

int searchMax(){
  int maxValue = -1;
  int index = -1;

  for(int i = 0;i < ARRAY_SIZE;i++){
    if(maxValue < (heightList[i])){
      maxValue = (heightList[i]);
      index = i;
    }
  }

  if(index != -1){
    (heightList[index]) = 0;
  }
  else{
    return -1;
  }

  return maxValue;
}

C++: #include <iostream>
#include <vector>
#include <algorithm>

int
main(void) {

    std::vector<int> v;
    for (int i = 0; i < 10; ++i) {
        int num;
        std::cin >> num;
        v.push_back(num);
    }   
    std::sort(v.begin(), v.end(), std::greater<int>() );

    for (int i = 0; i < 3; ++i) {                                                                                                                                                                   
        std::cout << v[i] << std::endl;
    }   

    return 0;
}

C++: #include <iostream>
#include <cstdlib>
#include <fstream>

int main(int argc, char *argv[]){
	std::ifstream datafile(argv[1]); //input datafile
	std::string str;
	int mt_height[10] = {}; //height of mountain
	int ans[3] = {}; // top 3 height of mountain. 0 -> no.1 1 -> no.2 2 -> no.3

	if(datafile.fail()){
		std::cout << "error : can't open this file." << std::endl;
		exit(1);
	}

	//input 10 height of mountain
	for(size_t i = 0; i < 10; i++){
		std::getline(datafile, str);
		sscanf(str.c_str(), "%d", &mt_height[i]);

		if((mt_height[i] < 0) || (mt_height[i] > 10000)){
			std::cout << "error : out of constraints" << std::endl;
			exit(1);
		}
	}

	//select top 3 height of mountain and sort ans[]
	for(size_t i = 0; i < 10; i++){
		if(ans[0] < mt_height[i]){
			ans[2] = ans[1];
			ans[1] = ans[0];
			ans[0] = mt_height[i];
		}else if(ans[1] < mt_height[i]){
			ans[2] = ans[1];
			ans[1] = mt_height[i];
		}else if(ans[2] < mt_height[i]){
			ans[2] = mt_height[i];
		}
	}

	//output ans[]
	for(size_t i = 0; i < 3; i++){
		std::cout << ans[i] << std::endl;
	}

	return 0;
}