Language: C++

#include <iostream>
#include <cstring>
#include <vector>
#include <set>
#include <map>
#include <sstream>
#include <cstdio>
#include <algorithm>
#include <stack>
#include <queue>
#include <cmath>
#include <iomanip>
#include <fstream>
//#include <bits/stdc++.h>
using namespace std;
typedef unsigned long long ll;
const ll INF = (1 << 30);
const ll inf = (1LL << 50LL);
const int  maxn = 1e6 + 5;
int n, W;
int weights[maxn], values[maxn];
ll dp[maxn];
ll rek(int at, int weight){
    if(at == -1) return 0;
    if(dp[weight] != -1){
        return dp[weight];
    }
    int ret = 0;
    if(weights[at] <= weight){
        ret = max(ret, rek(at - 1, weight - weights[at]) + values[at]);
    }
    ret = max(ret, rek(at - 1, weight));
    return dp[weight] = ret;
}
int main(int argc, const char * argv[]) {
    ios_base::sync_with_stdio(false);
//    ifstream cin("in.txt");
    cin >> n >> W;
    for(int i = 0; i < n; i ++){
        cin >> weights[i] >> values[i];
    }
    memset(dp, -1, sizeof dp);
    cout << rek(n - 1, W) << endl;
    return 0;
}


Compiler output:
a.cc: In function 'll rek(int, int)':
a.cc:30:18: error: no matching function for call to 'max(int&, ll)'
   30 |         ret = max(ret, rek(at - 1, weight - weights[at]) + values[at]);
      |               ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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:1:
/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:30:18: note:   deduced conflicting types for parameter 'const _Tp' ('int' and 'll' {aka 'long long unsigned int'})
   30 |         ret = max(ret, rek(at - 1, weight - weights[at]) + values[at]);
      |               ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/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:8:
/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:30:18: note:   mismatched types 'std::initializer_list<_Tp>' and 'int'
   30 |         ret = max(ret, rek(at - 1, weight - weights[at]) + values[at]);
      |               ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
a.cc:32:14: error: no matching function for call to 'max(int&, ll)'
   32 |     ret = max(ret, rek(at - 1, weight));
      |           ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~
/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:32:14: note:   deduced conflicting types for parameter 'const _Tp' ('int' and 'll' {aka 'long long unsigned int'})
   32 |     ret = max(ret, rek(at - 1, weight));
      |           ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~
/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
/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:32:14: note:   mismatched types 'std::initializer_list<_Tp>' and 'int'
   32 |     ret = max(ret, rek(at - 1, weight));
      |           ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~