Language: C++

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define rep(i, n) for(int i=0; i<(n); i++)
#define forin(in, n) for(int i=0; i<(n); i++) cin>>in[i]
#define forout(out) for(int i=0; i<(int)out.size(); i++) cout<<out[i]<<endl;

int binary_search(const vector<ll>& a ,ll key){
    int ng=-1, ok=(int)a.size();
    while(abs(ok-ng)>1){
        int mid=(ok+ng)/2;
        if(a[mid] < key){
            ng=mid;
        }else{
            ok=mid;
        }
    }
    return ng;
}

int main(){
    ll ans=0;
    ll n, m, k; cin>> n >> m >> k;
    vector<ll> a(n);
    vector<ll> b(m);

    vector<ll> sum_a(n);
    cin>>a[0];
    sum_a[0] = a[0];
    for(int i=1; i<n; i++){
        cin>>a[i];
        sum_a[i]=a[i] + sum_a[i-1];
    }


    vector<ll> sum_b(m);
    cin>>b[0];
    sum_b[0]=b[0];
    for(int i=1; i<m; i++){
        cin>>b[i];
        sum_b[i]=b[i]+sum_b[i-1];
    }
    rep(i, n){
        if(sum_a[i] <= k){
            ll tmp=binary_search(sum_b, k-sum_a[i]);
            ans = max(ans, i+tmp+2);
        }
    }
    ans = max(ans, binary_search(sum_b, k)+1);
    cout<<ans<<endl;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:49:14: error: no matching function for call to 'max(ll&, int)'
   49 |     ans = max(ans, binary_search(sum_b, k)+1);
      |           ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from /usr/include/c++/14/algorithm:60,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:51,
                 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:49:14: note:   deduced conflicting types for parameter 'const _Tp' ('long long int' and 'int')
   49 |     ans = max(ans, binary_search(sum_b, k)+1);
      |           ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/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:
/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:49:14: note:   mismatched types 'std::initializer_list<_Tp>' and 'long long int'
   49 |     ans = max(ans, binary_search(sum_b, k)+1);
      |           ~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~