Google-Code-Jam/square.cpp
2020-05-17 13:29:21 -05:00

74 lines
2 KiB
C++

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
// trick to iterate through directions
constexpr int dx[4] = { 1, 0, -1, 0 }, dy[4] = { 0, 1, 0, -1 };
int S[100001]; // skill levels
int neighbor[100001][4]; // array of neighbors for each competitor
int main() {
if (fopen("in", "r")) freopen("in", "r", stdin), freopen("out", "w", stdout);
int T; cin >> T;
for (int t = 1; t <= T; ++t) {
cout << "Case #" << t << ": ";
int R, C; cin >> R >> C;
ll ans = 0, sum = 0;
vector<int> check; // vector of candidate competitors to check
for (int i = 0; i < R; ++i) {
for (int j = 0; j < C; ++j) {
cin >> S[i * C + j]; sum += S[i * C + j];
check.push_back(i * C + j);
}
}
// checks if coordinates are out of range
auto valid = [&R, &C](const int& x, const int& y) {
return x >= 0 && x < R && y >= 0 && y < C;
};
// precompute neighbors
for (int i = 0; i < R; ++i) {
for (int j = 0; j < C; ++j) {
for (int d = 0; d < 4; ++d) {
int x = i + dx[d], y = j + dy[d]; // get neighbor
neighbor[i * C + j][d] = valid(x, y) ? x * C + y : -1;
}
}
}
while (1) { // simulate the competition
vector<int> elim; // vector to store eliminated competitors
for (auto& c : check) { // examine every candidate competitor
int i = c / C, j = c % C, sum = 0, num = 0;
if (S[c]) {
for (int d = 0; d < 4; ++d) {
if (neighbor[c][d] != -1) sum += S[neighbor[c][d]], ++num;
}
if (num * S[c] < sum) elim.push_back(c);
}
}
check.clear(); // clear check for finding candidates for next round
ans += sum;
for (auto& c : elim) {
int i = c / C, j = c % C;
if (S[c]) { // remove each competitor
sum -= S[c], S[c] = 0;
for (int d = 0; d < 4; ++d) if (neighbor[c][d] != -1) {
neighbor[neighbor[c][d]][(d + 2) % 4] = neighbor[c][(d + 2) % 4];
check.push_back(neighbor[c][d]);
}
}
}
if (elim.empty()) break; // if no one eliminated we can end the competition
}
cout << ans << '\n';
}
}