Submission #407027

#	Time	Username	Problem	Language	Result	Execution time	Memory
407027		LptN21	Baloni (COCI15_baloni)	C++14	100 / 100	113 ms	27356 KiB

baloni

#include <bits/stdc++.h>
using namespace std;
#define fastIO ios_base::sync_with_stdio(false), cin.tie(NULL), cout.tie(NULL);
#define FF first
#define SS second
#define pb push_back
#define sz(x) (int)x.size()
#define oo 1e9
#define eps 1e-9
#define PI acos(-1.0)
#define lb lower_bound
#define ub upper_bound
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> ii;
const int N = 1e6+7, M=1000+7;
const int MOD = 1e9+7;

int n, m, k, t;

int a[N];
vector<int> prv[N];

signed main() {
    //freopen("test.inp", "r", stdin);
    //freopen("test.out", "w", stdout);
    //fastIO;
    scanf("%d", &n);
    int ans=0;memset(prv, 0, sizeof prv);
    for(int i=1;i<=n;i++) scanf("%d", &a[i]);
    for(int j, i=n;i>0;i--) {
        prv[a[i]].pb(i);
        if(sz(prv[a[i]-1])) prv[a[i]-1].pop_back();
        else ans++;
    }
    printf("%d", ans);
    return 0;
}
/* stuff you should look for
    - int overflow, array bounds
    - special cases (n=1?)
    - do smth instead of do nothing and stay organized
    - WRITE STUFF DOWN
    - DONT JUST STICK ON ONE APPROACH
*/

Compilation message (stderr)

baloni.cpp: In function 'int main()':
baloni.cpp:29:40: warning: 'void* memset(void*, int, size_t)' clearing an object of type 'class std::vector<int>' with no trivial copy-assignment; use assignment or value-initialization instead [-Wclass-memaccess]
   29 |     int ans=0;memset(prv, 0, sizeof prv);
      |                                        ^
In file included from /usr/include/c++/10/vector:67,
                 from /usr/include/c++/10/queue:61,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:86,
                 from baloni.cpp:1:
/usr/include/c++/10/bits/stl_vector.h:389:11: note: 'class std::vector<int>' declared here
  389 |     class vector : protected _Vector_base<_Tp, _Alloc>
      |           ^~~~~~
baloni.cpp:31:13: warning: unused variable 'j' [-Wunused-variable]
   31 |     for(int j, i=n;i>0;i--) {
      |             ^
baloni.cpp:28:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   28 |     scanf("%d", &n);
      |     ~~~~~^~~~~~~~~~
baloni.cpp:30:32: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   30 |     for(int i=1;i<=n;i++) scanf("%d", &a[i]);
      |                           ~~~~~^~~~~~~~~~~~~

• Subtask 1: 100 / 100