Submission #444333

#	Time	Username	Problem	Language	Result	Execution time	Memory
444333		parsabahrami	The short shank; Redemption (BOI21_prison)	C++17	55 / 100	2089 ms	204160 KiB

prison

/* I do it for the glory */
#include <bits/stdc++.h>
 
using namespace std;
 
typedef long long int ll;
typedef pair<double, int> pii;
 
#define SZ(x)                       (int) x.size()
#define F                           first
#define S                           second
#define lc                          id << 1
#define rc                          lc | 1
 
const int N = 1e6 + 10, MOD = 1e9 + 7; const double eps = 1e-14;
int R[N], t[N], n, T, D; int seg[N << 2], dp[N][100];
 
void bld(int x, int id = 1, int l = 1, int r = n + 1) {
    if (r - l < 2) { seg[id] = dp[l][x] + l; return; }
    int md = (l + r) >> 1;
    bld(x, lc, l, md), bld(x, rc, md, r);
    seg[id] = min(seg[lc], seg[rc]);
}
 
int get(int ql, int qr, int id = 1, int l = 1, int r = n + 1) {
    if (qr <= l || r <= ql) return MOD;
    if (ql <= l && r <= qr) { return seg[id]; }
    int md = (l + r) >> 1;
    return min(get(ql, qr, lc, l, md), get(ql, qr, rc, md, r));
}
 
int main() {
    scanf("%d%d%d", &n, &D, &T);
    //assert(n <= N);
    for (int i = 1; i <= n; i++) 
        scanf("%d", &t[i]);
    for (int i = n; i; i--) {
        for (R[i] = i + 1; R[i] <= n && t[R[i]] - R[i] > t[i] - i; R[i] = R[R[i]]);
    }
    for (int i = n; i; i--) {
        if (R[i] <= min(n, i + T - t[i])) 
            R[i] = R[R[i]];
        else R[i] = min(n, i + T - t[i]);
        if (R[i] < i) R[i] = -1;
    }
    for (int i = n; i; i--) {
        if (R[i] < i) dp[i][0] = dp[i + 1][0];
        else dp[i][0] = (R[i] - i + 1) + dp[R[i] + 1][0];
    }
    for (int j = 1; j <= D; j++) {
        bld(j - 1);
        for (int i = n; i; i--) {
            if (R[i] < i) dp[i][j] = min(dp[i + 1][j - 1], dp[i + 1][j]);
            else {
                int x = get(i + 1, R[i] + 2);
                dp[i][j] = min(x - i, dp[R[i] + 1][j] + R[i] - i + 1);
            }
        }
    }
    printf("%d\n", dp[1][D]);
    return 0;
}
 

Compilation message (stderr)

prison.cpp: In function 'int main()':
prison.cpp:33:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   33 |     scanf("%d%d%d", &n, &D, &T);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~
prison.cpp:36:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   36 |         scanf("%d", &t[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