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| -rw-r--r-- | 21/open/balanced_slow.cpp | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/21/open/balanced_slow.cpp b/21/open/balanced_slow.cpp new file mode 100644 index 0000000..3f7c3e9 --- /dev/null +++ b/21/open/balanced_slow.cpp @@ -0,0 +1,73 @@ +#include <bits/stdc++.h> +#define f first +#define s second +using namespace std; +using ll = long long; +using ii = pair<int, int>; +constexpr int MX = 155, MOD = 1e9+7; + +inline void add(int & x, int y) { x += y; if (x > MOD) x -= MOD; } + +string S[MX]; + +struct fenwick_tree_2d { + int FT[MX][MX]; + fenwick_tree_2d() { memset(FT, 0, sizeof FT); } + inline void update(int x, int y, int v) { + for (int i = x+1; i < MX; i += i&-i) + for (int j = y+1; j < MX; j += j&-j) add(FT[i][j], v); + } + inline int query(int x, int y) { + int ret = 0; + for (int i = x+1; i > 0; i -= i&-i) + for (int j = y+1; j > 0; j -= j&-j) add(ret, FT[i][j]); + return ret; + } + inline int query(int xl, int xr, int yl, int yr) { + int ret = query(xr, yr); + add(ret, MOD-query(xl-1, yr)); + add(ret, MOD-query(xr, yl-1)); + add(ret, query(xl-1, yl-1)); + return ret; + } +} DP[MX][4]; + +int main() { + if (fopen("in", "r")) freopen("in", "r", stdin), freopen("out", "w", stdout); + cin.tie(0)->sync_with_stdio(0); + + int N; cin >> N; + for (int i = 0; i < N; ++i) cin >> S[i]; + + int ans = 0; + for (int i = 0; i < N; ++i) { + for (int a = 0; a < N; ++a) { + for (int b = a; b < N; ++b) { + if (S[i][b] != 'G') break; + + int sum = 1; + add(sum, DP[i][0].query(a, b, a, b)); + DP[i+1][0].update(a, b, sum); + add(ans, sum); + + sum = DP[i][1].query(a, b, b, N-1); + add(sum, DP[i][0].query(a, b, b+1, N-1)); + DP[i+1][1].update(a, b, sum); + add(ans, sum); + + sum = DP[i][2].query(0, a, a, b); + add(sum, DP[i][0].query(0, a-1, a, b)); + DP[i+1][2].update(a, b, sum); + add(ans, sum); + + sum = DP[i][3].query(0, a, b, N-1); + add(sum, DP[i][0].query(0, a-1, b+1, N-1)); + add(sum, DP[i][1].query(0, a-1, b, N-1)); + add(sum, DP[i][2].query(0, a, b+1, N-1)); + DP[i+1][3].update(a, b, sum); + add(ans, sum); + } + } + } + cout << ans%MOD; +} |