1 files changed, 103 insertions, 0 deletions
diff --git a/test/other/divideAndConquer.cpp b/test/other/divideAndConquer.cpp
new file mode 100644
index 0000000..a6fda9d
--- /dev/null
+++ b/test/other/divideAndConquer.cpp
@@ -0,0 +1,103 @@
+#include "../util.h"
+constexpr ll inf = LL::INF;
+#include <other/divideAndConquer.cpp>
+
+vector<vector<ll>> gen(int n) {
+	vector<vector<ll>> res(n, vector<ll>(n));
+	ll mi = 0;
+	for (ll a = n-1; a >= 0; a--) {
+		for (ll c = n-1; c >= a; c--) {
+			for (ll b = a; b <= c; b++) {
+				for (ll d = c; d < n; d++) {
+					res[a][c] = min(res[a][c], res[a][d] + res[b][c] - res[b][d]);
+				}
+			}
+			res[a][c] -= Random::integer<ll>(0, 1000);
+			mi = min(mi, res[a][c]);
+		}
+	}
+	for (auto& v : res) for (auto& x : v) x -= mi;
+	
+	for (ll a = 0; a < n; a++) {
+		for (ll b = a; b < n; b++) {
+			for (ll c = b; c < n; c++) {
+				for (ll d = c; d < n; d++) {
+					if (res[a][d] < 0 || res[a][d] + res[b][c] < res[a][c] + res[b][d]) {
+						 cerr << "invalid C array!" << FAIL;
+					}
+				}
+			}
+		}
+	}
+	return res;
+}
+
+vector<vector<ll>> genQuick(int n) {
+	vector<vector<ll>> res(n, vector<ll>(n));
+	for (ll a = n-1; a >= 0; a--) {
+		for (ll c = n-1; c >= a; c--) {
+			res[a][c] = (c-a) * (c - a) + Random::integer<ll>(0, 2);
+		}
+	}
+	return res;
+}
+
+/*ll naive(int n, int m) {
+	vector<vector<ll>> state(m+1, vector<ll>(n+1, inf));
+	state[0][0] = 0;
+	for (int i = 1; i <= m; i++) {
+		for (int j = 1; j <= n; j++) {
+			for (int k = 1; k <= j; k++) {
+				state[i][j] = min(state[i][j], state[i-1][k-1] + C[k-1][j-1]);
+			}
+		}
+	}
+	return state[m][n];
+}*/
+
+vector<ll> naive(int n) {
+	vector<vector<ll>> state(n+1, vector<ll>(n+1, inf));
+	state[0][0] = 0;
+	vector<ll> res(n+1, inf);
+	for (int i = 1; i <= n; i++) {
+		for (int j = 1; j <= n; j++) {
+			for (int k = 1; k <= j; k++) {
+				state[i][j] = min(state[i][j], state[i-1][k-1] + C[k-1][j-1]);
+			}
+		}
+		res[i] = state[i][n];
+	}
+	return res;
+}
+
+void stress_test() {
+	ll tests = 0;
+	for (ll i = 0; i < 1000; i++) {
+		auto n = Random::integer(10, 20);
+		C = gen(n);
+		auto expected = naive(n);
+		for (ll m = 1; m <= n; m++) {
+			auto got = calc(n, m);
+			if (got != expected[m]) cerr << "got: " << got << ", expected: " << expected[m] << FAIL;
+			tests++;
+		}
+	}
+	cerr << "tested random queries: " << tests << endl;
+}
+
+constexpr int N = 10'000;
+void performance_test() {
+	timer t;
+	C = genQuick(N);
+	t.start();
+	auto hash = calc(N, 32);
+	t.stop();
+	if (t.time > 50) cerr << "too slow: " << t.time << FAIL;
+	cerr << "tested performance: " << t.time << "ms (hash: " << hash << ")" << endl;
+}
+
+int main() {
+	stress_test();
+	performance_test();
+}
+