oj.uz

Submission #476321

# Submission time Handle Problem Language Result Execution time Memory
476321 2021-09-26T03:35:35 Z Mackerel_Pike 3D Histogram (COCI20_histogram) C++14
110 / 110
 148 ms 3404 KB 
#include <bits/stdc++.h>

using namespace std;

const int maxn = 2e5 + 5;

int n;
int a[maxn], b[maxn], f[maxn], g[maxn];
long long ans;
bool DEBUG;

inline void calc1(int l, int r, int ql, int qr){
  if(l > r)
    return;
  int md = l + r >> 1, pos = -1;
  long long ret = 0;
  for(int i = ql; i <= qr; ++i){
    long long res = 1ll * (i - md + 1) * min(f[md], f[i]) * min(g[md], g[i]);
    if(!~pos || res >= ret)
      ret = res, pos = i;
  }
  ans = max(ans, ret);
  calc1(l, md - 1, ql, pos);
  calc1(md + 1, r, pos, qr);
  return;
}

inline void calc2(int l, int r, int ql, int qr){
  if(l > r)
    return;
  int md = l + r >> 1, pos = -1;
  long long ret = 0;
  for(int i = ql; i <= qr; ++i){
    long long res = 1ll * (i - md + 1) * min(f[md], f[i]) * min(g[md], g[i]);
    if(!~pos || res >= ret)
      ret = res, pos = i;
  }
  ans = max(ans, ret);
  calc2(l, md - 1, pos, qr);
  calc2(md + 1, r, ql, pos);
  return;
}

inline void solve(int l, int r){
  if(l == r){
    ans = max(ans, 1ll * a[l] * b[l]);
    return;
  }
  int md = l + r >> 1;
  for(int i = md; i >= l; --i){
    f[i] = min(i == md ? 0x3f3f3f3f : f[i + 1], a[i]);
    g[i] = min(i == md ? 0x3f3f3f3f : g[i + 1], b[i]);
  }
  for(int i = md + 1; i <= r; ++i){
    f[i] = min(i == md + 1 ? 0x3f3f3f3f : f[i - 1], a[i]);
    g[i] = min(i == md + 1 ? 0x3f3f3f3f : g[i - 1], b[i]);
  }
  calc1(l, md, md + 1, r);
  calc2(l, md, md + 1, r);
  solve(l, md), solve(md + 1, r);
  return;
}

int main(){
  scanf("%d", &n);
  for(int i = 0; i < n; ++i)
    scanf("%d%d", a + i, b + i);

  solve(0, n - 1);

  printf("%lld\n", ans);
  return 0;
}

Compilation message

histogram.cpp: In function 'void calc1(int, int, int, int)':
histogram.cpp:15:14: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   15 |   int md = l + r >> 1, pos = -1;
      |            ~~^~~
histogram.cpp: In function 'void calc2(int, int, int, int)':
histogram.cpp:31:14: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   31 |   int md = l + r >> 1, pos = -1;
      |            ~~^~~
histogram.cpp: In function 'void solve(int, int)':
histogram.cpp:49:14: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   49 |   int md = l + r >> 1;
      |            ~~^~~
histogram.cpp: In function 'int main()':
histogram.cpp:65:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   65 |   scanf("%d", &n);
      |   ~~~~~^~~~~~~~~~
histogram.cpp:67:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   67 |     scanf("%d%d", a + i, b + i);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~

Subtask #1
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 332 KB Output is correct
2 Correct 1 ms 332 KB Output is correct
3 Correct 1 ms 332 KB Output is correct
4 Correct 2 ms 332 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 1 ms 332 KB Output is correct
7 Correct 1 ms 332 KB Output is correct
8 Correct 1 ms 332 KB Output is correct
9 Correct 1 ms 332 KB Output is correct
10 Correct 1 ms 332 KB Output is correct
11 Correct 0 ms 204 KB Output is correct
12 Correct 1 ms 332 KB Output is correct

Subtask #2
90.0 / 90.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 332 KB Output is correct
2 Correct 1 ms 332 KB Output is correct
3 Correct 1 ms 332 KB Output is correct
4 Correct 2 ms 332 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 1 ms 332 KB Output is correct
7 Correct 1 ms 332 KB Output is correct
8 Correct 1 ms 332 KB Output is correct
9 Correct 1 ms 332 KB Output is correct
10 Correct 1 ms 332 KB Output is correct
11 Correct 0 ms 204 KB Output is correct
12 Correct 1 ms 332 KB Output is correct
13 Correct 142 ms 3396 KB Output is correct
14 Correct 147 ms 3404 KB Output is correct
15 Correct 134 ms 3396 KB Output is correct
16 Correct 148 ms 3392 KB Output is correct
17 Correct 137 ms 3380 KB Output is correct
18 Correct 132 ms 3312 KB Output is correct
19 Correct 128 ms 3404 KB Output is correct
20 Correct 121 ms 3396 KB Output is correct
21 Correct 114 ms 3396 KB Output is correct
22 Correct 131 ms 3364 KB Output is correct
23 Correct 11 ms 588 KB Output is correct
24 Correct 120 ms 3396 KB Output is correct