Go: package main

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

func getsAsIntArray() (line []int) {
	scanner := bufio.NewScanner(os.Stdin)

	for scanner.Scan() {
		str := scanner.Text()
		if str == "" {
			break
		}
		data, err := strconv.Atoi(str)
		if err != nil {
			break
		}
		line = append(line, data)
	}

	return
}

func main() {

	lines := getsAsIntArray()
	sort.Sort(sort.Reverse(sort.IntSlice(lines)))
	for i, v := range lines {
		if i < 3 {
			fmt.Println(v)
		}
	}
}

C++: #include<iostream>
int main(void){
    int h;
    int t[3] = {0, 0, 0};
    for(int i = 0; i < 10; i++){
        std::cin >> h;
        for(int i = 0; i < 3; i++){
            if(t[i] <= h){
                switch(i){
                    case 0:
                        t[i+2] = t[i+1];
                        t[i+1] = t[i];
                        t[i] = h;
                        break;
                    case 1:
                        t[i+1] = t[i];
                        t[i] = h;
                        break;
                }
                break;
            }
        }
    }
    for(int i = 0; i < 3; i++){
        std::cout << t[i] << std::endl;
    }
    return 0;
}

C++: // clang-format off
#include <bits/stdc++.h>
#define int long long
#define main signed main()
// #define main int main()
#define loop(i, a, n) for (int i = (a); i < (n); i++)
#define rep(i, n) loop(i, 0, n)
#define all(v) (v).begin(), (v).end()
#define rall(v) (v).rbegin(), (v).rend()
#define prec(n) fixed << setprecision(n)
#define stlice(from, to) substr(from, (to) - (from) + 1)
#define pb push_back
#define mp make_pair
#define mt make_tuple
#define fi first
#define se second
using namespace std;
using pii = pair<int, int>;
using vi = vector<int>;
using vd = vector<double>;
using vc = vector<char>;
using vb = vector<bool>;
using vs = vector<string>;
using vpii = vector<pii>;
using vvi = vector<vi>;
using vvb = vector<vb>;
using vvpii = vector<vpii>;
template<typename A> using fn = function<A>;
constexpr int INF = sizeof(int) == sizeof(long long) ? 1000000000000000000LL : 1000000000;
constexpr int MOD = 1000000007;
constexpr double PI = acos(-1);
template<typename A, typename B> bool cmin(A &a, const B &b) { return a > b ? (a = b, true) : false; }
template<typename A, typename B> bool cmax(A &a, const B &b) { return a < b ? (a = b, true) : false; }
constexpr bool odd(const int &n) { return n & 1; }
constexpr bool even(const int &n) { return !odd(n); }
void solve();
main { solve(); return 0; }
// clang-format on

void solve() {
  while (true) {}
}

C++: #include<iostream>

using namespace std;

int main()
{
	int high[10] = { };
	int first = 0, second = 0, third = 0;
	
	for(int i = 0; i < 10; i++){
		cin >> high[i];
		
		if(first < high[i])
			first = high[i];
		else if(second < high[i])
			second = high[i];
		else if(third < high[i])
			third = high[i];
	}
	
	cout << first << endl << second << endl << third << endl;
	
	
	return 0;
}

C++: #include <iostream>
#include <vector>
#include <algorithm>
#include <queue>
using namespace std;

int main() {
    clock_t cTimeStart, cTimeEnd;
    cTimeStart = clock();           // 現在時刻
    int H[10];
    for(int i=0;i<10;++i){
    	cin>>H[i];
    }
    sort(H,H+10);
    for(int i=0;i<3;++i){
    	    cout<<H[9-i]<<endl;
    }

    cTimeEnd = clock();           // 現在時刻
//    cout<< "処理時間:" <<(cTimeEnd - cTimeStart)/1000 << "[ms]" << endl;

	return 0;
}

C++: #include<iostream>
#include<algorithm>
using namespace std;

int main(){

	int mountain[10];

	for(int i=0; i<10; i++){
		cin >> mountain [i];
	}
	sort(mountain,mountain+10);
	
	cout << mountain [9] << endl << mountain[8] << endl << mountain[7];
	
    return 0;
}

C++: 

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
#include<stdio.h>
  
int main(){
    int i,j,t,data[10];
      
    for(i=0;i<10;i++)
    {
        scanf("%d",&data[i]);
    }
      
    for(i=0;i<9;i++)
    {
        for(j=0;j<9-i;j++)
        {
            if(data[j]<data[j+1])
            {
                t=data[j];
                data[j]=data[j+1];
                data[j+1]=t;
            }
        }
    }
    for(i=0;i<3;i++)
    {
        printf("%d\n",data[i]);
    }
  
    return 0;

C++: #include<stdio.h>
int main(){
	int l[10],r[10]={-1};
	int i,j,k,c[10],n=0;
	for(i=0;i<10;i++){
		c[i]=11;
	}
	for(i=0;i<10;i++){
		scanf("%d",&l[i]);
	}
	for(j=0;j<10;j++){
		for(i=0;i<10;i++){
			for(k=0;k<10;k++){
				if(c[k]==i){
					n=1;
				}
			}
			if(!(n==1)){
				if(l[i]>=r[j]){
					r[j]=l[i];
					c[j]=i;
				}
			}
			n=0;
		}
	}
	for(i=0;i<3;i++){
		printf("%d\n",r[i]);
	}
	return 0;
}

C++: #include <iostream>
using namespace std;
int main(){
	int takasa[10];

	for (int i = 0; i < 10; i++) {
		cin >> takasa[i];
	}

	//????????????
	for (int i = 0; i < 9; i++) {
		for (int j = i+1; j < 10; j++) {
			if (takasa[i] <takasa[j]) {
				swap (takasa[i],takasa[j]);
			}
		}
	}
	
	for (int i = 0; i < 3; i++) {
		cout << takasa[i] << endl;
	}
	return 0;
}

C++: #include <algorithm>
#include <cstdio>
#include <functional>
#include <vector>

using namespace std;

int main() {
  vector<int> mountains;
  for (int i = 0; i < 10; i++) {
    int mountain;
    scanf("%d", &mountain);
    mountains.push_back(mountain);
  }
  sort(mountains.begin(), mountains.end(), greater<int>());
  for (int i = 0; i < 3; i++) {
    printf("%d\n", mountains[0]);
    mountains.erase(mountains.begin());
  }
}

C++: #include <stdio.h>

int main ()
{
    int a[10], i, j, temp, t;
    scanf ("%d", &t);
    while (t--){
    for (i=0; i<10; i++){
        scanf("%d", &a[i]);
    }
    for (i=0; i<10; i++){
        for (j=i+1; j<10; j++){
            if (a[i]<a[j])
            {
                temp = a[i];
                a[i] = a[j];
                a[j] = temp;
            }
        }
    }

        printf("%d\n", a[0]);
        printf("%d\n", a[1]);
        printf("%d\n", a[2]);
    }

    return 0;
}

C++: #include<algorithm>
a[10],i
main(){
    for(;i<10;scanf("%d",a+i++));

}

C++: #include <stdio.h>
#include <stdlib.h>

int compare(const void *a, const void *b)
{
  return *(int*)b-*(int*)a;
}

int main(void)
{
  int heights[10];
  int i;
  for(i=0; i<10; ++i) {
    scanf("%d", &heights[i]);
  }
  qsort(heights, 10, sizeof(int), compare);
  printf("%d\n", heights[0]);
  printf("%d\n", heights[1]);
  printf("%d\n", heights[2]);

  return 0;
}

C++: #include<iostream>
#include<vector>
using namespace std;
class ListofTop3Hills{ 
    public:
        void solve(vector<int> m){
            for(int i=0;i<10;i++){ 
                for(int j=m.size()-1;j>0;j--){ 
                    if(m[j-1]<m[j]){ 
                        int tmp=m[j-1];
                        m[j-1]=m[j];
                        m[j]=tmp;
                    }
                }
            }
            for(int i=0;i<3;i++)cout<<m[i]<<endl;
        }
}; 
int main(){
    vector<int> m(10);
    for(int i=0;i<10;i++){ 
        cin>>m[i];
    }
    ListofTop3Hills inst;
    inst.solve(m);
    return 0;
}

C++: #include<bits/stdc++.h>
#define ll long long int
#define FOR(i,a,b) for(ll i=(ll)(a);i<(ll)(b);i++)
#define REP(i,n) FOR(i,0,n)
#define REP1(i,n) FOR(i,1,n)
using namespace std;
 /*temp*/

int main(){
    int a[10];
    REP(i,10){
        cin >> a[i];
    }
    sort(a, a+10);
    cout << a[9] << '\n'
         << a[8] << '\n'
         << a[7] << '\n';
}