Submission #378017

#	Time	Username	Problem	Language	Result	Execution time	Memory
378017		WLZ	Wombats (IOI13_wombats)	C++14	100 / 100	12374 ms	197100 KiB

wombats

#include "wombats.h"
#include <bits/stdc++.h>
using namespace std;

const int INF = 0x3f3f3f3f;

int r, c;
vector< vector<int> > h, v;
vector<int> range;

vector< vector<int> > calc(int x) {
  vector< vector<int> > ans(c, vector<int>(c, INF)), pre(2, vector<int>(c, 0));
  for (int i = 0; i < 2; i++) for (int j = 1; j < c; j++) pre[i][j] = pre[i][j - 1] + h[x + i][j - 1];
  for (int i = 0; i < c; i++) {
    int mx = -INF;
    for (int j = 0; j < c; j++) {
      mx = max(mx, pre[1][j] - abs(pre[0][i] - pre[0][j]) - v[x][j]);
      ans[i][j] = min(ans[i][j], pre[1][j] - mx);
    }
    int mn = INF;
    for (int j = c - 1; j >= 0; j--) {
      mn = min(mn, abs(pre[0][i] - pre[0][j]) + v[x][j] + pre[1][j]);
      ans[i][j] = min(ans[i][j], mn - pre[1][j]);
    }
  }
  return move(ans);
}

vector< vector<int> > combine(const vector< vector<int> > &a, const vector< vector<int> > &b) {
  vector< vector<int> > ans(c, vector<int>(c, INF)), best(c, vector<int>(c, -1));
  for (int i = 0; i < c; i++) {
    for (int j = c - 1; j >= 0; j--) {
      int l = i == 0 ? 0 : best[i - 1][j], r = j == c - 1 ? c - 1 : best[i][j + 1];
      for (int k = l; k <= r; k++) {
        if (a[i][k] + b[k][j] < ans[i][j]) {
          ans[i][j] = a[i][k] + b[k][j];
          best[i][j] = k;
        }
      }
    }
  }
  return move(ans);
}

vector< vector<int> > calc(int l, int r) {
  vector< vector<int> > ans = calc(l);
  for (int i = l + 1; i < r; i++) ans = combine(ans, calc(i));
  return move(ans);
}

struct node {
  int l, r;
  vector< vector<int> > cost;
  node *left, *right;
} *root;

node *build(int l, int r) {
  if (l + 10 >= r) {
    for (int i = l; i < r; i++) range[i] = l;
    return new node{l, r, calc(l, r), nullptr, nullptr};
  }
  node *left = build(l, (l + r) / 2), *right = build((l + r) / 2, r);
  return new node{l, r, combine(left->cost, right->cost), left, right};
}

void update(node *cur, int x) {
  if (cur->left == nullptr) {
    assert(cur->l == x);
    cur->cost = calc(cur->l, cur->r);
    return;
  }
  if (cur->right->l <= x) update(cur->right, x);
  else update(cur->left, x);
  cur->cost = combine(cur->left->cost, cur->right->cost);
}

void init(int R, int C, int H[5000][200], int V[5000][200]) {
  r = R, c = C;
  h.assign(r, vector<int>(c - 1));
  for (int i = 0; i < r; i++) for (int j = 0; j < c - 1; j++) h[i][j] = H[i][j];
  v.assign(r - 1, vector<int>(c));
  for (int i = 0; i < r - 1; i++) for (int j = 0; j < c; j++) v[i][j] = V[i][j];
  range.resize(r - 1);
  root = build(0, r - 1);
}

void changeH(int P, int Q, int W) {
  h[P][Q] = W;
  if (P > 0) update(root, range[P - 1]);
  if (P < r - 1) update(root, range[P]);
}

void changeV(int P, int Q, int W) {
  v[P][Q] = W;
  update(root, range[P]);
}

int escape(int V1, int V2) {
  return root->cost[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 'std::vector<std::vector<int> > calc(int)':
wombats.cpp:26:14: warning: moving a local object in a return statement prevents copy elision [-Wpessimizing-move]
   26 |   return move(ans);
      |          ~~~~^~~~~
wombats.cpp:26:14: note: remove 'std::move' call
wombats.cpp: In function 'std::vector<std::vector<int> > combine(const std::vector<std::vector<int> >&, const std::vector<std::vector<int> >&)':
wombats.cpp:42:14: warning: moving a local object in a return statement prevents copy elision [-Wpessimizing-move]
   42 |   return move(ans);
      |          ~~~~^~~~~
wombats.cpp:42:14: note: remove 'std::move' call
wombats.cpp: In function 'std::vector<std::vector<int> > calc(int, int)':
wombats.cpp:48:14: warning: moving a local object in a return statement prevents copy elision [-Wpessimizing-move]
   48 |   return move(ans);
      |          ~~~~^~~~~
wombats.cpp:48:14: note: remove 'std::move' call

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