Submission #680058

#	Time	Username	Problem	Language	Result	Execution time	Memory
680058		bashkort	Wombats (IOI13_wombats)	C++17	100 / 100	13969 ms	39724 KiB

wombats

#include <bits/stdc++.h>
#include "wombats.h"

using namespace std;

inline bool ckmin(int &a, int b) {
    return (a > b) && (a = b, true);
}

constexpr int B = 200, R = 5000, C = 200, K = (R + B - 1) / B;
constexpr int N = (K + 3) * 4;

int r, c, need, sz = 1;
int dp[N][C][C], fr[K * 2][C][C], H[R][C], V[R][C];


void pull(int x) {
    memset(dp[x], 0x3f, sizeof(dp[x]));
    
    if (dp[x << 1 | 1][0][0] == -1) {
        memcpy(dp[x], dp[x << 1], sizeof(dp[x]));
        return;
    }
    
    for (int cc = 0; cc < c; ++cc) {
        function<void(int, int, int, int)> solve = [&](int l, int r, int optl, int optr) {
            if (l >= r) {
                return;
            }

            int mid = (l + r) >> 1;

            int opt = optl;

            for (int b = optl; b <= optr; ++b) {
                if (ckmin(dp[x][cc][mid], dp[x << 1][cc][b] + dp[x << 1 | 1][b][mid])) {
                    opt = b;
                }
            }

            solve(l, mid, optl, opt), solve(mid + 1, r, opt, optr);
        };
        solve(0, c, 0, c - 1);
    }
}

void update_fr(int L) {
    if (L < 0) {
        return;
    }

    int lim = max(0, B * L - 1);

    if (lim < r) {
        memset(fr[L], 0x3f, sizeof(fr[L]));
        for (int a = 0; a < c; ++a) {
            fr[L][a][a] = 0;
        }
        
        for (int i = min(r, B * (L + 1)) - 1; i >= lim; --i) {
            for (int a = 0; a < c - 1; ++a) {
                for (int cc = 0; cc < c; ++cc) {
                    ckmin(fr[L][a + 1][cc], fr[L][a][cc] + H[i][a]);
                }
            }
            for (int a = c - 2; a >= 0; --a) {
                for (int cc = 0; cc < c; ++cc) {
                    ckmin(fr[L][a][cc], fr[L][a + 1][cc] + H[i][a]);
                }
            }
            if (i != lim) {
                for (int a = 0; a < c; ++a) {
                    for (int cc = 0; cc < c; ++cc) {
                        fr[L][a][cc] += V[i - 1][a];
                    }
                }
            }
        }
    } else {
        memset(fr[L], -1, sizeof(fr[L]));
    }

    memcpy(dp[sz + L], fr[L], sizeof(dp[sz + L]));

    for (int x = sz + L; x >>= 1;) {
        pull(x);
    }
}

void init(int R, int C, int H[5000][200], int V[5000][200]) {
    r = R, c = C;
    memcpy(::H, H, sizeof(::H)), memcpy(::V, V, sizeof(::V));

    need = 2 + r / B;
    sz = 1 << __lg(need) + bool(need & (need - 1));
    for (int i = 0; i < sz; ++i) {
        update_fr(i);
    }
}

void changeH(int P, int Q, int W) {
    H[P][Q] = W;

    int L = P / B;

    update_fr(L);
    if ((P + 1) % B == 0 && L + 1 < need) {
        update_fr(L + 1);
    }
}

void changeV(int P, int Q, int W) {
    V[P][Q] = W;

    int L = (P + 1) / B;

    update_fr(L);
}

int escape(int V1, int V2) {
    return dp[1][V1][V2];
}

Compilation message (stderr)

grader.c: In function 'int main()':
grader.c:15:6: warning: variable 'res' set but not used [-Wunused-but-set-variable]
   15 |  int res;
      |      ^~~
wombats.cpp: In function 'void init(int, int, int (*)[200], int (*)[200])':
wombats.cpp:95:26: warning: suggest parentheses around '+' inside '<<' [-Wparentheses]
   95 |     sz = 1 << __lg(need) + bool(need & (need - 1));
      |               ~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 9 / 9
• Subtask 2: 12 / 12
• Subtask 3: 16 / 16
• Subtask 4: 18 / 18
• Subtask 5: 21 / 21
• Subtask 6: 24 / 24