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Submission #1105318

# Submission time Handle Problem Language Result Execution time Memory
1105318 2024-10-26T07:06:59 Z InvMOD Sjeckanje (COCI21_sjeckanje) C++14
110 / 110
 278 ms 30792 KB 
#include<bits/stdc++.h>

#define int long long

using namespace std;

using ll = long long;

const int N = 2e5+5;
const ll inf = 1e16;

int n, q, a[N], sub[N], dp[3][N], st[N<<2][2][2];

int get_dp()
{
    // dp[0]: sum of segment
    // dp[1]: creating segment min -> max
    // dp[2]: creating segment max -> min
    dp[0][0] = 0;
    dp[1][0] = dp[2][0] = -inf;

    for(int i = 1; i <= n; i++){
        dp[0][i] = max({dp[0][i-1], dp[1][i-1] + a[i], dp[2][i-1] - a[i]});
        dp[1][i] = max(dp[1][i-1], dp[0][i-1] - a[i]);
        dp[2][i] = max(dp[2][i-1], dp[0][i-1] + a[i]);
    }
    return dp[0][n];
}

//[0][0]: has the different sign with both start and end
//[0][1]: has the different sign with start and same with end
//[1][0]: has the same sign with start and different with end
//[1][1]: has the same sign with both start and end

void update(int id, int l, int r, int x){
    if(l == r){
        st[id][1][1] = (sub[l] < 0 ? -sub[l] : sub[l]);
        return;
    }
    else{
        int m = l+r>>1;
        if(x <= m) update(id<<1, l, m, x);
        else
            update(id<<1|1, m+1, r, x);

        // if mid sign and mid+1 sign is different
        if(sub[m] * sub[m+1] < 0){
            // our task is to make sure that mid sign and mid+1 sign always the same
            st[id][0][0] = max(st[id<<1][0][1] + st[id<<1|1][0][0], st[id<<1][0][0] + st[id<<1|1][1][0]);
            st[id][0][1] = max(st[id<<1][0][1] + st[id<<1|1][0][1], st[id<<1][0][0] + st[id<<1|1][1][1]);
            st[id][1][0] = max(st[id<<1][1][1] + st[id<<1|1][0][0], st[id<<1][1][0] + st[id<<1|1][1][0]);
            st[id][1][1] = max(st[id<<1][1][1] + st[id<<1|1][0][1], st[id<<1][1][0] + st[id<<1|1][1][1]);
        }
        else{
            // we can take anything from [L,MID], [R,MID]
            st[id][0][0] = max(st[id<<1][0][1], st[id<<1][0][0]) + max(st[id<<1|1][1][0], st[id<<1|1][0][0]);
            st[id][0][1] = max(st[id<<1][0][1], st[id<<1][0][0]) + max(st[id<<1|1][1][1], st[id<<1|1][0][1]);
            st[id][1][0] = max(st[id<<1][1][1], st[id<<1][1][0]) + max(st[id<<1|1][1][0], st[id<<1|1][0][0]);
            st[id][1][1] = max(st[id<<1][1][1], st[id<<1][1][0]) + max(st[id<<1|1][1][1], st[id<<1|1][0][1]);
        }
    }
    return;
}

void solve()
{
    cin >> n >> q;
    for(int i = 1; i <= n; i++){
        cin >> a[i];
        if(i-1){
            sub[i] = a[i] - a[i-1];
            update(1, 2, n, i);
        }
    }

   while(q--){
        int l,r,x; cin >> l >> r >> x;

        sub[l] += x;
        update(1, 2, n, l);

        if(r+1 <= n){
            sub[r+1] -= x;
            update(1, 2, n, r+1);
        }

        cout << max({st[1][0][0], st[1][0][1], st[1][1][0], st[1][1][1]}) <<"\n";
    }
    return;
}

int32_t main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);

    #define name "InvMOD"
    if(fopen(name".INP", "r")){
        freopen(name".INP", "r", stdin);
        freopen(name".OUT", "w", stdout);
    }

    solve();
    return 0;
}

Compilation message

Main.cpp: In function 'void update(long long int, long long int, long long int, long long int)':
Main.cpp:41:18: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   41 |         int m = l+r>>1;
      |                 ~^~
Main.cpp: In function 'int32_t main()':
Main.cpp:98:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   98 |         freopen(name".INP", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
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(name".OUT", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2384 KB Output is correct
2 Correct 1 ms 2384 KB Output is correct
3 Correct 1 ms 2548 KB Output is correct
4 Correct 1 ms 2436 KB Output is correct
5 Correct 1 ms 2384 KB Output is correct
6 Correct 1 ms 2384 KB Output is correct

Subtask #2
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2384 KB Output is correct
2 Correct 1 ms 2384 KB Output is correct
3 Correct 1 ms 2548 KB Output is correct
4 Correct 1 ms 2436 KB Output is correct
5 Correct 1 ms 2384 KB Output is correct
6 Correct 1 ms 2384 KB Output is correct
7 Correct 4 ms 4688 KB Output is correct
8 Correct 3 ms 4688 KB Output is correct
9 Correct 4 ms 4688 KB Output is correct
10 Correct 4 ms 4688 KB Output is correct
11 Correct 4 ms 4688 KB Output is correct
12 Correct 4 ms 4804 KB Output is correct

Subtask #3
55.0 / 55.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2384 KB Output is correct
2 Correct 1 ms 2384 KB Output is correct
3 Correct 1 ms 2548 KB Output is correct
4 Correct 1 ms 2436 KB Output is correct
5 Correct 1 ms 2384 KB Output is correct
6 Correct 1 ms 2384 KB Output is correct
7 Correct 4 ms 4688 KB Output is correct
8 Correct 3 ms 4688 KB Output is correct
9 Correct 4 ms 4688 KB Output is correct
10 Correct 4 ms 4688 KB Output is correct
11 Correct 4 ms 4688 KB Output is correct
12 Correct 4 ms 4804 KB Output is correct
13 Correct 240 ms 30024 KB Output is correct
14 Correct 230 ms 30164 KB Output is correct
15 Correct 258 ms 30024 KB Output is correct
16 Correct 278 ms 30028 KB Output is correct
17 Correct 226 ms 30036 KB Output is correct
18 Correct 227 ms 30792 KB Output is correct