oj.uz

Submission #351236

# Submission time Handle Problem Language Result Execution time Memory
351236 2021-01-19T16:55:29 Z spatarel Watching (JOI13_watching) C++17
100 / 100
 79 ms 8684 KB 
#include <stdio.h>
#include <algorithm>

const int MAX_N = 2000;

int n, p, q;
int a[1 + MAX_N];

int nextNForW[1 + MAX_N + 1];
int nextNFor2W[1 + MAX_N + 1];
int maxN[1 + MAX_N + 1][1 + MAX_N + 1];

void maxSelf(int &a, int b) {
  if (a < b) {
    a = b;
  }
}

bool isPossible(int w) {
  //printf("w = %d\n", w);
  int i = 1;
  int j = 1;
  while (i <= n) {
    if (j <= n && a[j] <= a[i] + w - 1) {
      j++;
    } else {
      nextNForW[i] = j - 1;
      //printf("%d ", nextNForW[i]);
      i++;
    }
  }
  nextNForW[n + 1] = n;
  //printf("\n");
  i = 1;
  j = 1;
  while (i <= n) {
    if (j <= n && a[j] <= a[i] + 2 * w - 1) {
      j++;
    } else {
      nextNFor2W[i] = j - 1;
      //printf("%d ", nextNFor2W[i]);
      i++;
    }
  }
  nextNFor2W[n + 1] = n;
  //printf("\n");
  
  for (int i = 0; i <= p; i++) {
    for (int j = 0; j <= q; j++) {
      maxN[i][j] = 0;
    }
  }
  for (int i = 0; i <= p; i++) {
    for (int j = 0; j <= q; j++) {
      maxSelf(maxN[i + 1][j], nextNForW[maxN[i][j] + 1]);
      maxSelf(maxN[i][j + 1], nextNFor2W[maxN[i][j] + 1]);
      //printf("%d ", maxN[i][j]);
    }
    //printf("\n");
  }
  return maxN[p][q] == n;
}

int main() {
  scanf("%d%d%d", &n, &p, &q);
  for (int i = 1; i <= n; i++) {
    scanf("%d", &a[i]);
  }
  std::sort(a + 1, a + 1 + n);
  int w;
  if (n <= p + q) {
    w = 1;
  } else {
    w = 0;
    for (int step = 1 << 29; step > 0; step >>= 1) {
      if (!isPossible(w + step)) {
        w += step;
      }
    }
    w++;
  }
  printf("%d\n", w);
  return 0;
}

Compilation message

watching.cpp: In function 'int main()':
watching.cpp:65:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   65 |   scanf("%d%d%d", &n, &p, &q);
      |   ~~~~~^~~~~~~~~~~~~~~~~~~~~~
watching.cpp:67:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   67 |     scanf("%d", &a[i]);
      |     ~~~~~^~~~~~~~~~~~~

Subtask #1
50.0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 364 KB Output is correct
2 Correct 0 ms 364 KB Output is correct
3 Correct 0 ms 364 KB Output is correct
4 Correct 0 ms 364 KB Output is correct
5 Correct 1 ms 364 KB Output is correct
6 Correct 1 ms 364 KB Output is correct
7 Correct 0 ms 364 KB Output is correct
8 Correct 1 ms 364 KB Output is correct
9 Correct 1 ms 364 KB Output is correct
10 Correct 1 ms 364 KB Output is correct
11 Correct 1 ms 620 KB Output is correct
12 Correct 1 ms 492 KB Output is correct
13 Correct 0 ms 364 KB Output is correct
14 Correct 0 ms 364 KB Output is correct
15 Correct 0 ms 364 KB Output is correct

Subtask #2
50.0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 364 KB Output is correct
2 Correct 1 ms 364 KB Output is correct
3 Correct 1 ms 364 KB Output is correct
4 Correct 1 ms 364 KB Output is correct
5 Correct 1 ms 364 KB Output is correct
6 Correct 1 ms 364 KB Output is correct
7 Correct 2 ms 384 KB Output is correct
8 Correct 11 ms 1260 KB Output is correct
9 Correct 11 ms 3692 KB Output is correct
10 Correct 21 ms 8684 KB Output is correct
11 Correct 14 ms 1004 KB Output is correct
12 Correct 79 ms 8044 KB Output is correct
13 Correct 1 ms 364 KB Output is correct
14 Correct 1 ms 364 KB Output is correct
15 Correct 1 ms 364 KB Output is correct