| # |
Submission time |
Handle |
Problem |
Language |
Result |
Execution time |
Memory |
| 554203 |
2022-04-28T01:37:36 Z |
SmolBrain |
Strah (COCI18_strah) |
C++17 |
|
179 ms |
8268 KB |
// Om Namah Shivaya
// GM in 96 days
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
template <class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long int ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define endl '\n'
#define pb push_back
#define conts continue
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define yes cout << "YES" << endl
#define no cout << "NO" << endl
#define ff first
#define ss second
#define ceil2(x,y) ((x+y-1) / (y))
#define sz(a) a.size()
#define setbits(x) __builtin_popcountll(x)
#ifndef ONLINE_JUDGE
#define debug(x) cout << #x <<" = "; print(x); cout << endl
#else
#define debug(x)
#endif
#define rep(i,n) for(int i = 0; i < n; ++i)
#define rep1(i,n) for(int i = 1; i <= n; ++i)
#define rev(i,s,e) for(int i = s; i >= e; --i)
#define trav(i,a) for(auto &i : a)
bool iseven(ll n) {if ((n & 1) == 0) return true; return false;}
void print(ll t) {cout << t;}
void print(int t) {cout << t;}
void print(string t) {cout << t;}
void print(char t) {cout << t;}
void print(double t) {cout << t;}
void print(ld t) {cout << t;}
template <class T, class V> void print(pair <T, V> p);
template <class T> void print(vector <T> v);
template <class T> void print(set <T> v);
template <class T, class V> void print(map <T, V> v);
template <class T> void print(multiset <T> v);
template <class T, class V> void print(pair <T, V> p) {cout << "{"; print(p.ff); cout << ","; print(p.ss); cout << "}";}
template <class T> void print(vector <T> v) {cout << "[ "; for (T i : v) {print(i); cout << " ";} cout << "]";}
template <class T> void print(set <T> v) {cout << "[ "; for (T i : v) {print(i); cout << " ";} cout << "]";}
template <class T> void print(multiset <T> v) {cout << "[ "; for (T i : v) {print(i); cout << " ";} cout << "]";}
template <class T, class V> void print(map <T, V> v) {cout << "[ "; for (auto i : v) {print(i); cout << " ";} cout << "]";}
template<typename T> void amin(T &a, T b) { a = min(a, b); }
template<typename T> void amax(T &a, T b) { a = max(a, b); }
void usaco(string filename) {
freopen((filename + ".in").c_str(), "r", stdin);
freopen((filename + ".out").c_str(), "w", stdout);
}
const int MOD = 1e9 + 7;
const int maxn = 1e5 + 5;
const int inf1 = 1e9 + 5;
const ll inf2 = ll(1e18) + 5;
void solve(int test_case)
{
// reference codes (thanks to the people who wrote these codes):
// https://oj.uz/submission/475660
// https://github.com/galletas1712/CompetitiveProgramming/blob/master/Olympiad/COCI/COCI18-strah.cpp
ll n, m; cin >> n >> m;
char a[n][m];
rep(i, n) rep(j, m) cin >> a[i][j];
vector<ll> height(m);
ll ans = 0;
auto sum = [&](ll l, ll r) {
return r * (r + 1) / 2 - l * (l - 1) / 2;
};
rep(i, n) {
rep(j, m) {
if (a[i][j] == '.') height[j]++;
else height[j] = 0;
}
vector<ll> nseleft(m, -1), nseright(m, m);
stack<ll> st;
rep(j, m) {
while (!st.empty() and height[j] <= height[st.top()]) {
nseright[st.top()] = j;
st.pop();
}
st.push(j);
}
while (!st.empty()) st.pop();
rev(j, m - 1, 0) {
while (!st.empty() and height[j] < height[st.top()]) {
nseleft[st.top()] = j;
st.pop();
}
st.push(j);
}
rep(j, m) {
/*
find the area of all rectangles passing through cell (i,j)
area = summation((y - x + 1) * 1 + (y - x + 1) * 2 + ... (y - x + 1) * h) for l <= x <= j and j <= y <= r
= summation((y - x + 1) * h * (h + 1) / 2)
= summation(y - x + 1) * h * (h + 1) / 2
how to calculate summation(y - x + 1) efficiently?
range1 = j - l + 1
range2 = r - j + 1
summation(y - x + 1)
= summation((y + 1) * range1) - summation(x * range2)
= summation(y + 1) * range1 - summation(x) * range2
summation(y + 1) and summation(x) can be calculated in O(1) because both x and y lie within a range and the sum of natural numbers in a range can be found out using the sum of natural numbers formula
*/
ll l = nseleft[j] + 1, r = nseright[j] - 1;
ll range1 = j - l + 1, range2 = r - j + 1;
ll val = sum(j + 1, r + 1) * range1 - sum(l, j) * range2;
val *= sum(1, height[j]);
ans += val;
}
}
cout << ans << endl;
}
int main()
{
fastio;
int t = 1;
// cin >> t;
rep1(i, t) {
solve(i);
}
return 0;
}
Compilation message
strah.cpp: In function 'void usaco(std::string)':
strah.cpp:64:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
64 | freopen((filename + ".in").c_str(), "r", stdin);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
strah.cpp:65:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
65 | freopen((filename + ".out").c_str(), "w", stdout);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
212 KB |
Output is correct |
| 2 |
Correct |
0 ms |
212 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
232 KB |
Output is correct |
| 2 |
Correct |
0 ms |
320 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
4 ms |
496 KB |
Output is correct |
| 2 |
Correct |
5 ms |
496 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
4 ms |
464 KB |
Output is correct |
| 2 |
Correct |
5 ms |
596 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
4 ms |
468 KB |
Output is correct |
| 2 |
Correct |
5 ms |
460 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
49 ms |
2372 KB |
Output is correct |
| 2 |
Correct |
111 ms |
5092 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
111 ms |
5068 KB |
Output is correct |
| 2 |
Correct |
179 ms |
7448 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
72 ms |
3400 KB |
Output is correct |
| 2 |
Correct |
126 ms |
5324 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
12 ms |
816 KB |
Output is correct |
| 2 |
Correct |
117 ms |
6096 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
144 ms |
8268 KB |
Output is correct |
| 2 |
Correct |
172 ms |
8184 KB |
Output is correct |
