Codeforces Round 684 - Problem A, B, C

Author: azecoder

Codeforces/1440A.cpp

@@ -0,0 +1,42 @@
+#include <bits/stdc++.h>
+
+#define MX 1e4+5
+
+using namespace std;
+
+typedef pair<int, int> pii;
+typedef vector<int> vi;
+typedef vector<pii> vii;
+
+
+void solve() {
+	//
+	int n, c0, c1, h;
+	cin >> n >> c0 >> c1 >> h;
+	
+	string s;
+	cin >> s;
+	
+	int cnt1 = 0;
+	for(char ch: s) {
+		if(ch == '1')
+			cnt1++;
+	}
+	int cnt0 = n - cnt1;
+	
+	int price0 = cnt1 * h + n * c0;
+	int price1 = cnt0 * h + n * c1;
+	int price2 = cnt0 * c0 + cnt1 * c1;
+	cout << min(min(price0, price1)) << "\n";
+}
+
+
+int main() {
+	
+	int T;	
+	cin >> T;
+	while(T--)
+		solve();
+
+	return 0;
+}

Codeforces/1440B.cpp

@@ -0,0 +1,54 @@
+#include <bits/stdc++.h>
+
+#define MX 1e4+5
+
+using namespace std;
+
+typedef pair<int, int> pii;
+typedef vector<int> vi;
+typedef vector<pii> vii;
+
+
+void solve() {
+	//
+	int n, k;
+	cin >> n >> k;
+	
+	int ll = n * k;
+	vi a(ll);
+	for(int i = 0; i < ll; i++)
+		cin >> a[i];
+
+	
+	if(n <= 2) {
+		long long sum = 0;
+		for(int i = 0; i < ll; i += n)
+			sum += a[i];
+		cout << sum << "\n";
+		return;
+	}
+	
+	int ss = int(n / 2) + n % 2 - 1;
+	int bb = n - ss;
+	
+	//cout << "sb: " << ss << " - " << bb << "\n";
+	
+	long long sum = 0;
+	for(int i = ss * k; i < ll; i += bb) {
+		//cout << "x: " << a[i] << "\n";
+		sum += a[i];
+	}
+	
+	cout << sum << "\n";
+}
+
+
+int main() {
+	
+	int T;	
+	cin >> T;
+	while(T--)
+		solve();
+
+	return 0;
+}

Codeforces/1440C.cpp

@@ -0,0 +1,128 @@
+#include <bits/stdc++.h>
+
+#define MX 1e4+5
+
+using namespace std;
+
+typedef pair<int, int> pii;
+typedef vector<int> vi;
+typedef vector<pii> vii;
+typedef vector<vi> vvi;
+
+
+
+
+void solve2(int i, int j, int isign, int jsign, vector<vii> &result) {
+	vii ll;
+	ll.push_back({i, j});
+	ll.push_back({i+isign, j});
+	ll.push_back({i+isign, j+jsign});
+	result.push_back(ll);
+	ll.clear();
+	ll.push_back({i+isign, j+jsign});
+	ll.push_back({i, j+jsign});
+	ll.push_back({i, j});
+	result.push_back(ll);
+	ll.clear();
+	ll.push_back({i+isign, j});
+	ll.push_back({i, j});
+	ll.push_back({i, j+jsign});
+	result.push_back(ll);
+	ll.clear();
+}
+
+void solve() {
+	//
+	int n, m;
+	cin >> n >> m;
+	
+	vector<vi> a;
+	for(int i = 0; i < n; i++) {
+		string s;
+		cin >> s;
+		
+		vi ll;
+		for(char ch: s)
+			ll.push_back(int(ch-'0'));
+		a.push_back(ll);
+	}
+	
+	vector<vii> result;
+	// remove all possible 3-ones in each 2x2 square
+	for(int i = 0; i < n-1; i++)
+	for(int j = 0; j < m-1; j++) {
+		int count1 = a[i][j] + a[i][j+1] + a[i+1][j] + a[i+1][j+1];
+		if(count1 == 3) {
+			vii ll;
+			for(int ii = 0; ii <= 1; ii++)
+			for(int jj = 0; jj <= 1; jj++)
+				if(a[i+ii][j+jj])
+					ll.push_back({i+ii, j+jj});
+			result.push_back(ll);
+			a[i][j] = a[i][j+1] = a[i+1][j] = a[i+1][j+1] = 0;
+		} else if(count1 == 4) {
+			vii ll;
+			ll.push_back({i, j});
+			ll.push_back({i, j+1});
+			ll.push_back({i+1, j});
+			result.push_back(ll);
+			a[i][j] = a[i][j+1] = a[i+1][j] = 0;
+		}
+	}
+	
+	// solve for 1 or 2 ones in 2x2 square
+	for(int i = 0; i < n-1; i++)
+	for(int j = 0; j < m-1; j++) {
+		int count1 = a[i][j] + a[i][j+1] + a[i+1][j] + a[i+1][j+1];
+		if(count1 == 1) {
+			if(a[i][j]) {
+				a[i][j] = 0;
+				solve2(i, j, 1, 1, result);
+			} else if(a[i][j+1]) {
+				a[i][j+1] = 0;
+				solve2(i, j+1, 1, -1, result);
+			} else if(a[i+1][j]) {
+				a[i+1][j] = 0;
+				solve2(i+1, j, -1, 1, result);
+			} else if(a[i+1][j+1]) {
+				a[i+1][j+1] = 0;
+				solve2(i+1, j+1, -1, -1, result);
+			}
+		} else if(count1 == 2) {
+			vii l0, l1;
+			for(int ii = 0; ii <= 1; ii++)
+			for(int jj = 0; jj <= 1; jj++)
+				if(a[i+ii][j+jj]) {
+					l1.push_back({i+ii, j+jj});
+					a[i+ii][j+jj] = 0;
+				} else
+					l0.push_back({i+ii, j+jj});
+			l1.push_back(l0[0]);
+			result.push_back(l1);
+			int isign = -1, jsign = -1;
+			if(l0[0].first == 0)	isign = 1;
+			if(l0[0].second == 0)	jsign = 1;
+			solve2(l0[0].first, l0[0].second, isign, jsign, result);
+		}
+	}
+	
+	cout << result.size() << "\n";
+	for(vii lres: result) {
+		for(pii x: lres)
+			cout << x.first+1 << " " << x.second+1 << " ";
+		cout << "\n";
+	}
+	
+}
+
+
+int main() {
+	//
+	ios_base::sync_with_stdio(false);
+	int T;	
+	cin >> T;
+	while(T--)
+		solve();
+
+	return 0;
+}