Submission #407301

#	Time	Username	Problem	Language	Result	Execution time	Memory
407301		mat_v	The short shank; Redemption (BOI21_prison)	C++14	55 / 100	2079 ms	8516 KiB

prison

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/rope>

#define ff(i,a,b) for(int (i) = (a); (i) <= (b); ++(i))
#define fb(i,a,b) for(int (i) = (a); (i) >= (b); --(i))
#define mod 998244353
#define xx first
#define yy second
#define all(a) (a).begin(), (a).end()
#define pb push_back
#define ll long long
#define pii pair<int,int>

using namespace std;
using namespace __gnu_pbds;
typedef tree<int, null_type, less<int>,rb_tree_tag, tree_order_statistics_node_update> ordered_set;/// find_by_order(x)(x+1th) , order_of_key() (strictly less)
mt19937 rnd(chrono::steady_clock::now().time_since_epoch().count());


int n,d,t;
int niz[500005];

int dp[500005];
int ans[500005][2];
int nxt[500005];
int seg[4 * 100005];


int kveri(int node, int l, int r, int levo, int desno){
    if(l > r || levo > desno)return 1e9;
    if(r < levo || desno < l)return 1e9;
    if(l >= levo && r <= desno)return seg[node];
    int mid = (l + r) / 2;
    return min(kveri(node * 2, l, mid, levo, desno), kveri(node * 2 + 1, mid + 1, r, levo, desno));
}
void init(int node, int l, int r){
    if(l == r){
        seg[node] = 1e9;
        return;
    }
    int mid = (l + r) / 2;
    init(node * 2, l, mid);
    init(node * 2 + 1, mid + 1, r);
    seg[node] = 1e9;
}
void update(int node, int l, int r, int poz, int val){
    if(l == r){
        seg[node] = val;
        return;
    }
    int mid = (l + r) / 2;
    if(poz <= mid)update(node * 2, l, mid, poz, val);
    else update(node * 2 + 1, mid + 1, r, poz, val);
    seg[node] = min(seg[node * 2], seg[node * 2 + 1]);
}

int main()
{

    ios_base::sync_with_stdio(false); cin.tie(0);

    cin >> n >> d >> t;
    ff(i,1,n){
        cin >> niz[i];
        niz[i] -= i;
    }
    d = min(n,d);
    stack<int> s;
    fb(i,n,1){
        if(s.empty()){
            nxt[i] = n+1;
            s.push(i);
            continue;
        }
        while(!s.empty() && niz[s.top()]>niz[i]){
            s.pop();
        }
        if(s.empty())nxt[i] = n+1;
        else{
            nxt[i] = s.top();
        }
        s.push(i);
    }
    int mn = niz[1];
    ff(i,1,n){
        mn = min(niz[i], mn);
        if(mn <= t-i)ans[i][0]++;
        ans[i][0] += ans[i - 1][0];
    }
    fb(i,n,1){
        int kaj = nxt[i] - 1;
        int rch = t - (niz[i] + i);
        if(rch < 0){
            ans[i][1] = ans[i + 1][1];
            continue;
        }
        ans[i][1] = ans[nxt[i]][1] + min(rch + 1, nxt[i]-1-i+1);
    }
    if(d == 1){
        int sol = 1e9;
        ff(i,1,n){
            sol = min(sol, ans[i][0] + ans[i+1][1]);
        }
        cout << sol << "\n";
        return 0;
    }

    ff(j,0,d){
        if(j == 0){
            fb(i,n,1){
                dp[i] = ans[i][1];
                update(1,1,n,i,i+dp[i]);
            }
            continue;
        }
        fb(i,n,1){
            dp[i] = dp[nxt[i]];

            int r = nxt[i] - 1;
            int reach = t - (i + niz[i]);
            if(reach < 0){
                dp[i] = dp[i + 1];
                continue;
            }
            dp[i] += min(reach+1,nxt[i]-1-i+1);
            r = min(r, i + reach);
            dp[i] = min(dp[i], kveri(1,1,n,i,r)-i);
        }
        ff(i,1,n)update(1,1,n,i,i+dp[i]);
    }
    cout << dp[1] << "\n";
    return 0;
}

Compilation message (stderr)

prison.cpp: In function 'int main()':
prison.cpp:6:27: warning: unnecessary parentheses in declaration of 'i' [-Wparentheses]
    6 | #define ff(i,a,b) for(int (i) = (a); (i) <= (b); ++(i))
      |                           ^
prison.cpp:65:5: note: in expansion of macro 'ff'
   65 |     ff(i,1,n){
      |     ^~
prison.cpp:7:27: warning: unnecessary parentheses in declaration of 'i' [-Wparentheses]
    7 | #define fb(i,a,b) for(int (i) = (a); (i) >= (b); --(i))
      |                           ^
prison.cpp:71:5: note: in expansion of macro 'fb'
   71 |     fb(i,n,1){
      |     ^~
prison.cpp:6:27: warning: unnecessary parentheses in declaration of 'i' [-Wparentheses]
    6 | #define ff(i,a,b) for(int (i) = (a); (i) <= (b); ++(i))
      |                           ^
prison.cpp:87:5: note: in expansion of macro 'ff'
   87 |     ff(i,1,n){
      |     ^~
prison.cpp:7:27: warning: unnecessary parentheses in declaration of 'i' [-Wparentheses]
    7 | #define fb(i,a,b) for(int (i) = (a); (i) >= (b); --(i))
      |                           ^
prison.cpp:92:5: note: in expansion of macro 'fb'
   92 |     fb(i,n,1){
      |     ^~
prison.cpp:93:13: warning: unused variable 'kaj' [-Wunused-variable]
   93 |         int kaj = nxt[i] - 1;
      |             ^~~
prison.cpp:6:27: warning: unnecessary parentheses in declaration of 'i' [-Wparentheses]
    6 | #define ff(i,a,b) for(int (i) = (a); (i) <= (b); ++(i))
      |                           ^
prison.cpp:103:9: note: in expansion of macro 'ff'
  103 |         ff(i,1,n){
      |         ^~
prison.cpp:6:27: warning: unnecessary parentheses in declaration of 'j' [-Wparentheses]
    6 | #define ff(i,a,b) for(int (i) = (a); (i) <= (b); ++(i))
      |                           ^
prison.cpp:110:5: note: in expansion of macro 'ff'
  110 |     ff(j,0,d){
      |     ^~
prison.cpp:7:27: warning: unnecessary parentheses in declaration of 'i' [-Wparentheses]
    7 | #define fb(i,a,b) for(int (i) = (a); (i) >= (b); --(i))
      |                           ^
prison.cpp:112:13: note: in expansion of macro 'fb'
  112 |             fb(i,n,1){
      |             ^~
prison.cpp:7:27: warning: unnecessary parentheses in declaration of 'i' [-Wparentheses]
    7 | #define fb(i,a,b) for(int (i) = (a); (i) >= (b); --(i))
      |                           ^
prison.cpp:118:9: note: in expansion of macro 'fb'
  118 |         fb(i,n,1){
      |         ^~
prison.cpp:6:27: warning: unnecessary parentheses in declaration of 'i' [-Wparentheses]
    6 | #define ff(i,a,b) for(int (i) = (a); (i) <= (b); ++(i))
      |                           ^
prison.cpp:131:9: note: in expansion of macro 'ff'
  131 |         ff(i,1,n)update(1,1,n,i,i+dp[i]);
      |         ^~

• Subtask 1: 15 / 15
• Subtask 2: 10 / 10
• Subtask 3: 20 / 20
• Subtask 4: 10 / 10
• Subtask 5: 0 / 25
• Subtask 6: 0 / 20