Language: C++

#include<bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int i = 0; i < (n); i++)
using P = pair<int, int>;
using ll = long long;
const int INF = 1001001001;

int main() {
    int n,m,k;
    cin >> n >> m >> k;
    vector<ll> a(n+1), b(m+1);
    a[0] = 0; b[0] = 0;
    rep(i, n){
        int x; cin >> x;
        a[i+1] = a[i] + x;
    }
    rep(i, m){
        int x; cin >> x;
        b[i+1] = b[i] + x;
    }

    ll ans = 0;
    int best = m;
    rep(i, n+1){
        if(a[i] > k) break;
        while(b[best] > k - a[i]) best--;
        ans = max(ans, i+best);
    }
    cout << ans << endl;



    cin >> a[0];
    for(int i = 1; i < n; i++){
        int x; cin >> x;
        a[i] = a[i-1] + x;
    }
    cin >> b[0];
    for(int i = 1; i < m; i++){
        int x; cin >> x;
        b[i] = b[i-1] + x;
    }

    // for(auto& x: b){
    //     cout << x << endl;
    // }
    ll ans = 0;
    int best = m-1;
    for(ll i = 0; i < n; i++){
        // cout << "i=" << i << endl;
        if(a[i] > k) break;
        for(ll j = best; j >= 0; j--){
            // cout << b[j] << "=" << k-a[i] << endl;
            if(b[j] <= k - a[i]){
                best = j;
                // cout << i+1 << " " << j+1 << endl;
                ans = max(ans, i+1 + j+1);
                // cout << ans << endl;
                break;
            }
            if(j==0) ans = max(ans, i+1);
        }
    }
    cout << ans << endl;
    return 0;
}

Compiler output:
a.cc: In function 'int main()':
a.cc:27:18: error: no matching function for call to 'max(ll&, int)'
   27 |         ans = max(ans, i+best);
      |               ~~~^~~~~~~~~~~~~
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:27:18: note:   deduced conflicting types for parameter 'const _Tp' ('long long int' and 'int')
   27 |         ans = max(ans, i+best);
      |               ~~~^~~~~~~~~~~~~
/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:27:18: note:   mismatched types 'std::initializer_list<_Tp>' and 'long long int'
   27 |         ans = max(ans, i+best);
      |               ~~~^~~~~~~~~~~~~
a.cc:47:8: error: redeclaration of 'll ans'
   47 |     ll ans = 0;
      |        ^~~
a.cc:22:8: note: 'll ans' previously declared here
   22 |     ll ans = 0;
      |        ^~~
a.cc:48:9: error: redeclaration of 'int best'
   48 |     int best = m-1;
      |         ^~~~
a.cc:23:9: note: 'int best' previously declared here
   23 |     int best = m;
      |         ^~~~