Submission #962177

#	Time	Username	Problem	Language	Result	Execution time	Memory
962177		danikoynov	Wombats (IOI13_wombats)	C++14	76 / 100	20061 ms	91304 KiB

wombats

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

using namespace std;

const int maxr = 5010, maxc = 210;
const int maxblock = sqrt(maxr) + 10;
void precalculate();
int h[maxr][maxc], v[maxr][maxc], dp[maxblock][maxc][maxc];
int r, c, block_size;

struct node
{
     int t[maxc][maxc];

     node()
     {
          for (int i = 0; i < maxc; i ++)
               for (int j = 0; j < maxc; j ++)
          {
               t[i][j] = 0;
          }
     }
};

const int inf = 2e9 + 10;

node tree[4 * maxblock];
void unite(int root, int row)
{
     for (int i = 0; i < c; i ++)
     for (int j = 0; j < c; j ++)
     tree[root].t[i][j] = inf;

     for (int i = 0; i < c; i ++)
          for (int j = 0; j < c; j ++)
          for (int k = 0; k < c; k ++)
          {
               tree[root].t[i][j] = min(tree[root].t[i][j], tree[root * 2].t[i][k] + tree[root * 2 + 1].t[k][j] + v[row - 1][k]);
          }

}

void get_leaf(int root, int bl)
{
     for (int i = 0; i < c; i ++)
          for (int j = 0; j < c; j ++)
          tree[root].t[i][j] = dp[bl][i][j];
}

void build(int root, int left, int right)
{
     if (left == right)
     {
          get_leaf(root, left);
          return;
     }

     int mid = (left + right) / 2;
     build(root * 2, left, mid);
     build(root * 2 + 1, mid + 1, right);

     unite(root, (mid + 1) * block_size);
}

void update(int root, int left, int right, int pivot)
{
     if (left == right)
     {
          get_leaf(root, left);
          return;
     }

     int mid = (left + right) / 2;
     if (pivot <= mid)
          update(root * 2, left, mid, pivot);
     else
          update(root * 2 + 1, mid + 1, right, pivot);

     unite(root, (mid + 1) * block_size);
}

int m;
void init(int R, int C, int H[5000][200], int V[5000][200]) {
    /* ... */
    block_size = sqrt(R) + 1; /// maybe by 10 ???
    r = R;
    c = C;
    for (int i = 0; i < R - 1; i ++)
     for (int j = 0; j < C; j ++)
     v[i][j] = V[i][j];

    for (int i = 0; i < R; i ++)
     for (int j = 0; j < C - 1; j ++)
     h[i][j] = H[i][j];

     precalculate();
     m = (r - 1) / block_size;
     build(1, 0, m);
}


int fp[2][maxc];
void fix_row(int i)
{
     for (int j = 1; j < c; j ++)
     {
          fp[i & 1][j] = min(fp[i & 1][j], fp[i & 1][j - 1] + h[i][j - 1]);
     }
     for (int j = c - 2; j >= 0; j --)
     {
          fp[i & 1][j] = min(fp[i & 1][j], fp[i & 1][j + 1] + h[i][j]);
     }
}


void calc_block(int bl)
{

     int st = bl * block_size;
     int en = (bl + 1) * block_size - 1;

     en = min(en, r - 1);

     for (int d = 0; d < c; d ++)
     {
          for (int j = 0; j < c; j ++)
          {
               fp[0][j] = fp[1][j] = inf;
          }

          fp[st & 1][d] = 0;
          fix_row(st);

          for (int i = st + 1; i <= en; i ++)
          {
               for (int j = 0; j < c; j ++)
               {
                    fp[i & 1][j] = fp[(i - 1) & 1][j] + v[i - 1][j];
               }
               fix_row(i);
          }

          for (int j = 0; j < c; j ++)
          {
               dp[bl][d][j] = fp[en & 1][j];
          }
     }

}


void precalculate()
{
        for (int bl = 0; bl <= (r - 1) / block_size; bl ++)
     {

         /// cout << "calc block " << endl;
          calc_block(bl);
     }
     ///exit(0);
}

void changeH(int P, int Q, int W) {
    /* ... */
    h[P][Q] = W;
    calc_block(P / block_size);
    update(1, 0, m, P / block_size);
}

void changeV(int P, int Q, int W) {
    /* ... */
    v[P][Q] = W;
    calc_block(P / block_size);
    update(1, 0, m, P / block_size);
}


int arr[maxc], temp[maxc];
int escape(int V1, int V2)
{
     return tree[1].t[V1][V2];
     int v1 = V1, v2 = V2;
     for (int j = 0; j < c; j ++)
          arr[j] = dp[0][v1][j];

     for (int bl = 1; bl <= (r - 1) / block_size; bl ++)
     {
          int t = bl * block_size;
          for (int j = 0; j < c; j ++)
          {
               arr[j] = arr[j] + v[t - 1][j];
          }

          for (int j = 1; j < c; j ++)
          {
               arr[j] = min(arr[j], arr[j - 1] + h[t][j - 1]);
          }
          for (int j = c - 2; j >= 0; j --)
          {
               arr[j] = min(arr[j], arr[j + 1] + h[t][j]);
          }

          for (int j = 0; j < c; j ++)
               temp[j] = inf;

          for (int j = 0; j < c; j ++)
          {
               for (int d = 0; d < c; d ++)
                    temp[j] =min(temp[j], arr[d] + dp[bl][d][j]);
          }

          for (int j = 0; j < c; j ++)
               arr[j] = temp[j];
     }

     return arr[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:93:5: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
   93 |     for (int i = 0; i < R; i ++)
      |     ^~~
wombats.cpp:97:6: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
   97 |      precalculate();
      |      ^~~~~~~~~~~~

• Subtask 1: 9 / 9
• Subtask 2: 12 / 12
• Subtask 3: 16 / 16
• Subtask 4: 18 / 18
• Subtask 5: 21 / 21
• Subtask 6: 0 / 24