Go: package main
// 三角形の形は辺の長さで決まる． 順番に３つの正整数が与えられたとき， 辺の長さがそれらの値と一致する三角形が存在するかどうかを調べ,
//  存在するなら鋭角三角形，直角三角形，鈍角三角形のいずれかを判定し， 次の入力へ進む． 三角形が存在しないとき， それまでに入力された，
// 三角形，直角三角形，鋭角三角形，鈍角三角形の 個数を空白で区切って出力し， それ以降の入力は無視して終了する
// 入力の中には必ず三角形が存在しないようなものがある と仮定してよい. 入力の行数は判らないが各行には３つの正整数が空白で区切って書かれている．
//  ただし，各整数は100 以下とする.

// return
// 三角形 直角三角形　鈍角三角形 鈍角三角形
import (
	"os"
	"fmt"
	"bufio"
)


var sc = bufio.NewScanner(os.Stdin)

func max(a, b, c int) (int, int, int) {
	if a > b {
		if b > c {
			return a, b, c
		} else {
			return a, c, b
		}
	} else {
		if a > c {
			return b, a, c
		} else {
			return b, c, a
		}
	}
}

func find_trianges(a, b, c int) string {
	a, b, c = max(a, b, c)
	r := b*b + c*c
	if a*a > r {
		return "obtuse_triangle"
	} else if a*a < r {
		return "sharped_triangle"
	} else {
		return "right_triangle"
	}
}

func main() {
	s := bufio.NewScanner(os.Stdin)
	var t, r_t, s_t, o_t int = 0, 0, 0, 0
	for s.Scan() {
		var a, b, c int
		fmt.Sscan(s.Text(), &a, &b, &c)
			a, b, c = max(a, b, c)
			if (a < b + c) {
				r := find_trianges(a, b, c)
				switch r {
				case "right_triangle":
					r_t++
				case "sharped_triangle":
					s_t++
				case "obtuse_triangle":
					r_t++
				}
				t++
			}	else {
				break
			}
			
	}
	fmt.Println(t, r_t, s_t, o_t)
}

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

int main() {
        int a, b, c, ab, cc;
        int i, j, x;
        int ai=0, dn=0, tk=0, sa=0;

        while(1) {
                cin >> a >> b >> c;
                if (a > b) {
                        x = b;
                        b = a;
                        a = x;
                }
                if (b > c) {
                        x = c;
                        c = b;
                        b = x;
                }
                if ((a + b) <= c) {
                        break;
                }
                sa++;
                ab = (a * a) + (b * b);
                cc = c * c;
                if (ab == cc) {
                        tk++;
                } else {
                        if (ab > cc) ai++;
                        if (ab < cc) dn++;
                }
        }
        cout << sa << " " << tk << " " << ai << " " << dn << endl;
        return 0;
}

C++: #include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
#define _USE_MATH_DEFINES
using namespace std;

int main() {
	int a, b, c;
	int tri = 0;
	int acte = 0;
	int right = 0;
	int obtuse = 0;
	vector<int> t(3);
	while (cin >> a >> b >> c) {
		t[0] = a;
		t[1] = b;
		t[2] = c;
		sort(t.begin(), t.end());
		a = pow(t[0], 2);
		b = pow(t[1], 2);
		c = pow(t[2], 2);
		if (t[0] + t[1] > t[2]) {
			tri++;
			if (a + b == c) {
				right++;
			}
			else if (a + b > c){
				acte++;
			}
			else if (a + b < c) {
				obtuse++;
			}
		}
	}
	cout << tri << " " << right << " " << acte << " " << obtuse << endl;
	return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)n; i++)
#define rep2(i, s, n) for (int i = s; i < (int)n; i++)
#define all(obj) obj.begin(), obj.end()
#define debug(x) cerr << #x << ":" << x << "\n"
#define vdebug(vec) cerr << #vec << ":"; for (auto e : vec) cerr << e << " "; cout << "\n"
#define YN(f) cout << (f ? "YES" : "NO") << endl
#define Yn(f) cout << (f ? "Yes" : "No") << endl
#define yn(f) cout << (f ? "yes" : "no") << endl
using ll = long long;
using vi = vector<int>;
using vvi = vector<vi>;
using pii = pair<int, int>;

int main () {
	int a, b, c;
	int ac = 0, rt = 0, ob = 0;
	while (true) {
		cin >> a >> b >> c;
		if (a == 0 && b == 0 && c == 0) break;
		if (a > b) swap(a, b);
		if (b > c) swap(b, c);
		if (c >= a + b) {
			cout << ac + rt + ob << " " << rt << " " << ac << " " << ob << endl;
			break;
		} else {
			int x = a * a + b * b - c * c;
			if (x > 0) ac++;
			else if (x == 0) rt++;
			else if (x < 0) ob++;
		}
	}
}

C++: /**
 * File    : JOI_2005_triangle_types.cpp
 * Author  : Kazune Takahashi
 * Created : 2018-3-8 21:20:52
 * Powered by Visual Studio Code
 */

#include <iostream>
#include <iomanip>   // << fixed << setprecision(xxx)
#include <algorithm> // do { } while ( next_permutation(A, A+xxx) ) ;
#include <vector>
#include <string> // to_string(nnn) // substr(m, n) // stoi(nnn)
#include <complex>
#include <tuple>
#include <queue>
#include <stack>
#include <map> // if (M.find(key) != M.end()) { }
#include <set>
#include <random> // random_device rd; mt19937 mt(rd());
#include <cctype>
#include <cassert>
#include <cmath>
#include <cstdio>
#include <cstdlib>
using namespace std;

#define DEBUG 0 // change 0 -> 1 if we need debug.

typedef long long ll;

// const int dx[4] = {1, 0, -1, 0};
// const int dy[4] = {0, 1, 0, -1};

// const int C = 1e6+10;
// const ll M = 1000000007;

int cnt[3] = {0, 0, 0};

int main()
{
  int a[3];
  while (cin >> a[0] >> a[1] >> a[2])
  {
    sort(a, a + 3);
    if (a[0] + a[1] <= a[2])
    {
      cout << cnt[0] + cnt[1] + cnt[2] << " "
           << cnt[0] << " " << cnt[1] << " " << cnt[2] << endl;
      return 0;
    }
    int s = a[0] * a[0] + a[1] * a[1];
    int t = a[2] * a[2];
    if (s < t)
    {
      cnt[2]++;
    }
    else if (s == t)
    {
      cnt[1]++;
    }
    else
    {
      cnt[0]++;
    }
  }
}

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

main()
{
  double a, b, c;
  int chokaku = 0, eikaku = 0, donkaku = 0;
  
  while(1){
    scanf("%lf %lf %lf", &a, &b, &c);
    if ( a + b > c && a + c > b && b + c > a ) {
      if ( a*a + b*b == c*c || a*a + c*c == b*b || b*b + c*c == a*a) {
	chokaku++;
      } else if ( asin(a/b) < M_PI / 2. && asin(a/c) < M_PI / 2. && asin(b/c) < M_PI / 2) {
	eikaku++;
      } else {
	donkaku++;
      }
    } else {
      break;
    }
  }
  
  printf("%d %d %d %d\n", eikaku+donkaku+chokaku, chokaku, donkaku, eikaku);
  
  return (0);
}

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

using namespace std;

int main() {
	
	int Length[3];
	int Triangle[4] = {0};
	bool flag = 0;
	
	while( cin >> Length[0] >> Length[1] >> Length[2]) {
	
	sort(Length, Length+3);
	
	if( Length[0] + Length[1] <= Length[2] ) flag = 1;
	if(flag == 1) continue;
	
	if( Length[0] * Length[0] + Length[1] * Length[1] 
	== Length[3] * Length[3] )
	Triangle[1]++;
	
	else if(Length[0] * Length[0] + Length[1] * Length[1] 
	< Length[3] * Length[3] )
	Triangle[2]++;
	
	else
	Triangle[3]++;
	
	}
	Triangle[0] += ( Triangle[1] + Triangle[2] + Triangle[3] );
	cout << Triangle[0] << " " << Triangle[1] << " "
		 << Triangle[2] << " " << Triangle[3] << "\n";
	return 0;
}

C++: #include<iostream>
#include<algorithm>
#include<cstdio>
#include<cmath>
#include<math.h>
#include<string>
#include<string.h>
#include<stack>
#include<queue>
#include<vector>
#include<utility>
#include<set>
#include<map>
#include<stdlib.h>
#include<iomanip>

using namespace std;

#define ll long long
#define ld long double
#define EPS 0.0000000001
#define INF 1e9
#define MOD 1000000007
#define rep(i,n) for(i=0;i<n;i++)
#define loop(i,a,n) for(i=a;i<n;i++)
#define all(in) in.begin(),in.end()
#define shosu(x) fixed<<setprecision(x)
#define first F
#define second S

typedef vector<int> vi;
typedef pair<int,int> pii;

int main(void) {
  vi l(3);
  vi n(4,0);
  while(scanf("%d %d %d",&l[0],&l[1],&l[2])!=EOF){
    sort(all(l));
    if(l[0]+l[1]>l[2])n[0]++;
    else continue;
    double cosine=double(l[0]*l[0]+l[1]*l[1]-l[2]*l[2])/(2*l[0]*l[1]);
    if(cosine==0)n[1]++;
    else if(cosine>0)n[2]++;
    else if(cosine<0)n[3]++;
  }
  printf("%d %d %d %d\n",n[0],n[1],n[2],n[3]);
}