Submission #1040462

#	Time	Username	Problem	Language	Result	Execution time	Memory
1040462		Requiem	Sjeckanje (COCI21_sjeckanje)	C++17	55 / 110	52 ms	564 KiB

Main

#include<bits/stdc++.h>
#define int long long
#define pb push_back
#define fast ios_base::sync_with_stdio(false), cin.tie(nullptr), cout.tie(nullptr);
#define MOD 1000000007
#define inf 1e18
#define fi first
#define se second
#define FOR(i,a,b) for(int i=a;i<=b;i++)
#define FORD(i,a,b) for(int i=a;i>=b;i--)
#define sz(a) ((int)(a).size())
#define endl '\n'
#define pi 3.14159265359
#define TASKNAME "sjeckanje"
template<typename T> bool maximize(T &res, const T &val) { if (res < val){ res = val; return true; }; return false; }
template<typename T> bool minimize(T &res, const T &val) { if (res > val){ res = val; return true; }; return false; }
using namespace std;
typedef pair<int,int> ii;
typedef pair<int,ii> iii;
typedef vector<int> vi;

int n, q;
int a[3003];

namespace subtask2{
    bool check(){
        return n <= 3000 and q <= 3000;
    }

    /**
       Nhan xet cua ta la ta se dung cai difference array roi dp tren do
       Khi chuyen sang difference array thi ta co cac luu y:
       - Cac doan duoc chon phai co cung dau.
       - Cac doan duoc chon phai cach nhau 1 phan tu.
    **/

    int differenceArray[3003], dp[3030][2];

    //dp[i][j]: cho biet day con co tong lon nhat khi xet den vi tri i va j la dang duong hay am
    void update(int l, int r, int x){
         differenceArray[l] += x;
         differenceArray[r + 1] -= x;
    }

   int get(){
         int consNegative = 0, consPositive = 0;
         memset(dp, -0x3f, sizeof(dp));
         dp[1][0] = dp[1][1] = 0;

         for(int i = 1; i <= n; i++){
             for(int j = 0; j < 2; j++){
                 if (dp[i][j] > -inf){
//                     cout << i << ' ' << j <<' ' << dp[i][j] << endl;
                     if (j == 0) {
                         if (differenceArray[i + 1] > 0) maximize(dp[i + 1][0], dp[i][j] + differenceArray[i + 1]);
                     }
                     else {
                         if (differenceArray[i + 1] < 0) maximize(dp[i + 1][1], dp[i][j] - differenceArray[i + 1]);
                     }
                     maximize(dp[i + 1][0], dp[i][j]);
                     maximize(dp[i + 1][1], dp[i][j]);

                 }

             }
         }
         return max(dp[n][0], dp[n][1]);

    }
    void solve(){
        for(int i = 1; i <= n; i++){
            cin >> a[i];
            differenceArray[i] = a[i] - a[i - 1];
        }
//        cout << get();

        for(int i = 1; i <= q; i++){
            int l, r, x;
            cin >> l >> r >> x;
            update(l, r, x);
            cout << get() << endl;
        }
    }
}

namespace subtask3{
    bool check(){
         return true;
    }

    void solve(){

    }
}
main()
{
    fast;
    if (fopen(TASKNAME".inp","r")){
        freopen(TASKNAME".inp","r",stdin);
        freopen(TASKNAME".out","w",stdout);
    }
    cin >> n >> q;
    if (subtask2::check()) return subtask2::solve(), 0;
}
/**
Warning:
- MLE / TLE?
- Gioi han mang?
- Gia tri max phai luon gan cho -INF
- long long co can thiet khong?
- tran mang.
- code can than hon
- Nho sinh test de tranh RTE / TLE

--> Coi lai truoc khi nop
**/

Compilation message (stderr)

Main.cpp: In function 'long long int subtask2::get()':
Main.cpp:46:14: warning: unused variable 'consNegative' [-Wunused-variable]
   46 |          int consNegative = 0, consPositive = 0;
      |              ^~~~~~~~~~~~
Main.cpp:46:32: warning: unused variable 'consPositive' [-Wunused-variable]
   46 |          int consNegative = 0, consPositive = 0;
      |                                ^~~~~~~~~~~~
Main.cpp: At global scope:
Main.cpp:95:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   95 | main()
      | ^~~~
Main.cpp: In function 'int main()':
Main.cpp:99:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   99 |         freopen(TASKNAME".inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:100:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  100 |         freopen(TASKNAME".out","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 15 / 15
• Subtask 2: 40 / 40
• Subtask 3: 0 / 55