Submission #820596

#	Time	Username	Problem	Language	Result	Execution time	Memory
820596		flash	Bitaro the Brave (JOI19_ho_t1)	C++17	100 / 100	408 ms	114772 KiB

joi2019_ho_t1

#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;
using namespace chrono;

// mt19937 rng((int) std::chrono::steady_clock::now().time_since_epoch().count());
/*
template <class T> using ordered_set = tree <T, null_type, less <T>, rb_tree_tag, tree_order_statistics_node_update>;
*/

//***************** CONSTANTS *****************

const int MXN = 2e5;
const int mod = 1000000007;

//***************** GLOBAL VARIABLES *****************



//***************** AUXILIARY STRUCTS *****************



//***************** MAIN BODY *****************

void solve(){
	int H, W;
	cin >> H >> W;

	int grid[H][W];

	for(int i = 0; i < H; i++)
		for(int j = 0; j < W; j++){
			char x;
			cin >> x;

			if(x == 'J') grid[i][j] = 2;
			if(x == 'O') grid[i][j] = 0;
			if(x == 'I') grid[i][j] = 1;
		}

	int orbs[H][W];
	for(int i = 0; i < H; i++){
		orbs[i][W - 1] = (grid[i][W - 1] == 0 ? 1 : 0);
		for(int j = W - 2; j >= 0; --j){
			orbs[i][j] = orbs[i][j + 1] + (grid[i][j] == 0 ? 1 : 0); 
		}
	}

	int ingots[H][W];
	for(int j = 0; j < W; j++){
		ingots[H - 1][j] = (grid[H - 1][j] == 1 ? 1 : 0);
		for(int i = H - 2; i >= 0; --i){
			ingots[i][j] = ingots[i + 1][j] + (grid[i][j] == 1 ? 1 : 0);
		}
	}

	int64_t ans = 0;

	for(int i = 0; i < H; i++){
		for(int j = 0; j < W; j++){
			if(grid[i][j] != 2)
				continue;

			ans += orbs[i][j] * 1LL * ingots[i][j];
		}
	}

	cout << ans << '\n';
}

//***************** *****************

int32_t main(){
	ios_base::sync_with_stdio(NULL);
	cin.tie(NULL);

	#ifdef LOCAL
		auto begin = high_resolution_clock::now();
	#endif

	int tc = 1;
	// cin >> tc; 
	for (int t = 0; t < tc; t++)
		solve()
;
	#ifdef LOCAL 
		auto end = high_resolution_clock::now();
		cout << fixed << setprecision(4);
		cout << "Execution Time: " << duration_cast<duration<double>>(end - begin).count() << "seconds" << endl;
	#endif

	return 0;
}

/*
If code gives a WA, check for the following : 
1. I/O format

2. Are you clearing all global variables in between tests if multitests are a thing

3. Can you definitively prove the logic
*/

/*
JO
I
*/

• Subtask 1: 20 / 20
• Subtask 2: 30 / 30
• Subtask 3: 50 / 50