Language: C++

/***************************************************
 * Problem Name : D - Triangles.cpp
 * Problem Link : https://atcoder.jp/contests/abc143/tasks/abc143_d
 * OJ           : atCoder
 * Verdict      : Trying
 * Date         : 2019-11-23
 * Problem Type :
 * Author Name  : Saikat Sharma
 * University   : CSE, MBSTU
 ***************************************************/
#include <iostream>
#include <cstdio>
#include <cmath>
#include <algorithm>
#include <climits>
#include <cstring>
#include <string>
#include <sstream>
#include <vector>
#include <queue>
#include <list>
#include <unordered_map>
#include <unordered_set>
#include <cstdlib>
#include <deque>
#include <stack>
#include <bitset>
#include <cassert>
#include <map>
#include <set>
#include <cassert>
#include <iomanip>
#include <random>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;
typedef long long ll;
typedef unsigned long long ull;

#define __FastIO ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0)
#define __FileRead freopen ("input.txt", "r", stdin)
#define __FileWrite freopen ("output.txt", "w", stdout)
#define SET(a,v) memset(a,v,sizeof(a))
#define SZ(v) (int)v.size()
#define pii pair<int,int>
#define pil pair <int, ll>
#define pli pair <ll, int>
#define pll pair <ll, ll>
#define debug cout <<"######\n"
#define debug1(x) cout <<"### " << x << " ###\n"
#define debug2(x,y) cout <<"# " << x <<" : "<< y <<" #\n"
#define nl cout << "\n";
#define sp cout << " ";
#define sl(n) scanf("%lld", &n)
#define sf(n) scanf("%lf", &n)
#define si(n) scanf("%d", &n)
#define ss(n) scanf("%s", n)
#define pf(n) scanf("%d", n)
#define pfl(n) scanf("%lld", n)
#define all(v) v.begin(), v.end()
#define rall(v) v.begin(), v.end()
#define srt(v) sort(v.begin(), v.end())
#define r_srt(v) sort(v.rbegin(), v.rend())
#define rev(v) reverse(v.begin(), v.end())
#define Sqr(x) ((x)*(x))
#define Mod(x, m) ((((x) % (m)) + (m)) % (m))
#define max3(a, b, c) max(a, max(b, c))
#define min3(a, b, c) min(a, min(b, c))
#define pb push_back
#define mk make_pair
#define MAX 100005
#define INF 1000000009
#define MOD 1000000007

template<class T>
using min_heap = priority_queue<T, std::vector<T>, std::greater<T>>;
template<typename T>
using ordered_set  = tree<T, null_type, less<T>, rb_tree_tag,
      tree_order_statistics_node_update>;

template <typename T> string toString ( T Number ) {
    stringstream ss;
    ss << Number;
    return ss.str();
}
template<typename T> int toInt (T str) {
    stringstream ss;
    ss << str;
    int num;
    ss >> num;
    return num;
}
ll lcm (ll a, ll b) {
    return a * b / __gcd (a, b);
}
/************************************ Code Start Here ******************************************************/
int main () {
    __FastIO;
    //~ cout << setprecision (10);
    //~ cout << fixed;
    int n;
    cin >> n;
    vector<int>vec (n);

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

    sort (all (vec) );
    ll cnt = 0;

    for (int i = 0; i < n-1; i++) {
        for (int j = i + 1; j < n; j++) {
            int sum = (vec[i] + vec[j]);
            ll lw = (lower_bound (all (vec), sum) - vec.begin());
            ll up = upper_bound (all (vec), vec[j]) - vec.begin();
            //~ cout << sum << " " << lw << "\n";
            
            cnt += max(0, lw-up);
        }
    }

    cout << cnt << "\n";
    return 0;
}


Compiler output:
a.cc: In function 'int main()':
a.cc:121:23: error: no matching function for call to 'max(int, ll)'
  121 |             cnt += max(0, lw-up);
      |                    ~~~^~~~~~~~~~
In file included from /usr/include/c++/14/string:51,
                 from /usr/include/c++/14/bits/locale_classes.h:40,
                 from /usr/include/c++/14/bits/ios_base.h:41,
                 from /usr/include/c++/14/ios:44,
                 from /usr/include/c++/14/ostream:40,
                 from /usr/include/c++/14/iostream:41,
                 from a.cc:11:
/usr/include/c++/14/bits/stl_algobase.h:257:5: note: candidate: 'template<class _Tp> constexpr const _Tp& std::max(const _Tp&, const _Tp&)'
  257 |     max(const _Tp& __a, const _Tp& __b)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:257:5: note:   template argument deduction/substitution failed:
a.cc:121:23: note:   deduced conflicting types for parameter 'const _Tp' ('int' and 'll' {aka 'long long int'})
  121 |             cnt += max(0, lw-up);
      |                    ~~~^~~~~~~~~~
/usr/include/c++/14/bits/stl_algobase.h:303:5: note: candidate: 'template<class _Tp, class _Compare> constexpr const _Tp& std::max(const _Tp&, const _Tp&, _Compare)'
  303 |     max(const _Tp& __a, const _Tp& __b, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algobase.h:303:5: note:   candidate expects 3 arguments, 2 provided
In file included from /usr/include/c++/14/algorithm:61,
                 from a.cc:14:
/usr/include/c++/14/bits/stl_algo.h:5706:5: note: candidate: 'template<class _Tp> constexpr _Tp std::max(initializer_list<_Tp>)'
 5706 |     max(initializer_list<_Tp> __l)
      |     ^~~
/usr/include/c++/14/bits/stl_algo.h:5706:5: note:   candidate expects 1 argument, 2 provided
/usr/include/c++/14/bits/stl_algo.h:5716:5: note: candidate: 'template<class _Tp, class _Compare> constexpr _Tp std::max(initializer_list<_Tp>, _Compare)'
 5716 |     max(initializer_list<_Tp> __l, _Compare __comp)
      |     ^~~
/usr/include/c++/14/bits/stl_algo.h:5716:5: note:   template argument deduction/substitution failed:
a.cc:121:23: note:   mismatched types 'std::initializer_list<_Tp>' and 'int'
  121 |             cnt += max(0, lw-up);
      |                    ~~~^~~~~~~~~~