Submission #1113780

#	Time	Username	Problem	Language	Result	Execution time	Memory
1113780		kiethm07	Sjeckanje (COCI21_sjeckanje)	C++11	110 / 110	599 ms	51784 KiB

Main

#include <bits/stdc++.h>

#define pii pair<int,int>
#define pli pair<long long,pii>
#define fi first
#define se second

#define vi vector<int>
#define vii vector<pii>
#define all(x) x.begin(),x.end()

using namespace std;

typedef long long ll;
typedef long double ld;

const int inf = 1e9;
const ll linf = 1e16;
const double pi = acos(-1);
const int N = 2e5 + 5;

ll a[N];
ll d[N];
ll dp[N][2];
int n,q;

ll brute(){
    dp[0][0] = dp[0][1] = 0;
    dp[1][0] = dp[1][1] = 0;
    if (d[1] > 0) dp[1][0] = d[1];
    else dp[1][1] = -d[1];
    for (int i = 2; i < n; i++){
        dp[i][0] = dp[i - 1][0];
        dp[i][1] = dp[i - 1][1];
        if (d[i] > 0){
            dp[i][0] = max(dp[i][0], dp[i - 1][0] + d[i]);
            dp[i][0] = max(dp[i][0], max(dp[i - 2][0], dp[i - 2][1]) + d[i]);
        }
        else{
            dp[i][1] = max(dp[i][1], dp[i - 1][1] - d[i]);
            dp[i][1] = max(dp[i][1], max(dp[i - 2][0], dp[i - 2][1]) - d[i]);
        }
    }
    return max(dp[n - 1][0], dp[n - 1][1]);
}

struct node{
    ll left = 0, right = 0;
    ll val[2][2];
    node(ll x){
        left = right = x;
        val[0][0] = val[0][1] = val[1][0] = val[1][1] = 0;
        val[1][1] = abs(x);
    }
};

node combine(node& a,node& b){
    node n(0);
    n.left = a.left;
    n.right = b.right;
    ///[i - j][k - l]
    for (int i = 0; i < 2; i++){
        for (int j = 0; j < 2; j++){
            for (int k = 0; k < 2; k++){
                for (int l = 0; l < 2; l++){
                    if (j && k){
                        if ((a.right >= 0 && b.left >= 0) || (a.right <= 0 && b.left <= 0)){
                            n.val[i][l] = max(n.val[i][l], a.val[i][j] + b.val[k][l]);
                        }
                    }
                    else n.val[i][l] = max(n.val[i][l], a.val[i][j] + b.val[k][l]);
                }
            }
        }
    }
    return n;
}

class IT{
private:
    vector<node> t;
    ll getAns(node& f){
        return max({f.val[0][0],f.val[0][1],f.val[1][0],f.val[1][1]});
    }
public:
    IT (int n){
        t.resize(4 * n,node(0));
    }
    void build(int id,int l,int r){
        if (l == r){
            t[id] = node(d[l]);
            return;
        }
        int mid = (l + r) / 2;
        build(id * 2,l,mid);
        build(id * 2 + 1,mid + 1,r);
        t[id] = combine(t[id * 2],t[id * 2 + 1]);
//        cout << l << " " << r << " " << getAns(t[id]) << "\n";
    }
    void update(int id,int l,int r,int i,int val){
        if (l > i || r < i) return;
        if (l == r){
            t[id] = node(val);
            return;
        }
        int mid = (l + r) / 2;
        update(id * 2,l,mid,i,val);
        update(id * 2 + 1,mid + 1,r,i,val);
        t[id] = combine(t[id * 2],t[id * 2 + 1]);
    }
    ll query(int id,int l,int r,int u,int v){
        if (l > v || r < u) return 0;
        if (l >= u && r <= v){
            return getAns(t[id]);
        }
        return -1;
    }
};

void solve(){
    IT t(n);
    t.build(1,1,n - 1);
    while(q--){
        int l,r,x;
        cin >> l >> r >> x;
        d[l - 1] += x;
        d[r] -= x;
        if (l - 1 >= 1) t.update(1,1,n - 1,l - 1,d[l - 1]);
        if (r <= n - 1) t.update(1,1,n - 1,r,d[r]);
        cout << t.query(1,1,n - 1,1,n - 1) << "\n";
//        cout << brute() << "\n";
    }
}

int main(){-
    #define TEXT "a"
    cin.tie(0) -> sync_with_stdio(0);
    if (fopen(TEXT".inp","r")){
        freopen(TEXT".inp","r",stdin);
        freopen(TEXT".out","w",stdout);
    }
    cin >> n >> q;
    for (int i = 1; i <= n; i++){
        cin >> a[i];
    }
    for (int i = 1; i < n; i++) d[i] = a[i + 1] - a[i];
    solve();
    return 0;
}

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:135:12: warning: value computed is not used [-Wunused-value]
  135 | int main(){-
      |            ^
  136 |     #define TEXT "a"
      |     ~~~~~~~~~~~~~~~~
  137 |     cin.tie(0) -> sync_with_stdio(0);
      |     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:139:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  139 |         freopen(TEXT".inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
Main.cpp:140:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  140 |         freopen(TEXT".out","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

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