Solution for Codeforces Problems

codeforces/B/1097B.cpp

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+// Codeforces 2019
+// Vinicius Rodrigues 15.10.2019
+// Petr and a Combination Lock : Problem 1097B
+
+#include <stdio.h>
+#include <vector>
+
+using namespace std;
+
+void input(vector<int> *vec)
+{
+	int rots, num;
+	scanf("%d", &rots);
+	for(int i = 0; i < rots; i++)
+	{
+		scanf("%d", &num);
+		vec -> push_back(num);
+	}
+}
+
+int sumWithBitmask(vector<int> nums, int bitmask)
+{
+	int summation = 0;
+	for(int i = 0; i < nums.size(); i++)
+	{
+		if(bitmask bitand 1 << i)
+			summation += nums[i];
+		else
+			summation -= nums[i];
+	} 
+	return summation;
+}
+
+bool checkIfValid(vector<int> nums)
+{
+	for(int i = 0; i < 1 << nums.size(); i++)
+		if(sumWithBitmask(nums, i) % 360 == 0)
+			return true;
+	return false;
+}
+
+int main()
+{
+	vector<int> nums(0);
+	input(&nums);
+	if(checkIfValid(nums))
+		printf("YES\n");
+	else
+		printf("NO\n");
+}

codeforces/B/476B.cpp

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+// Codeforces 2019
+// Vinicius Rodrigues 15.10.2019
+// Dreamoon and WiFi : Problem 476B
+
+#include <iostream>
+#include <string>
+#include <algorithm>
+#include <cmath>
+#include <stdio.h>
+
+using namespace std;
+
+double pfat(int n, int k)
+{
+	if(n == 0 or n == k) return 1;
+
+	double factor = 1.0f;
+	for(int i = k+1; i <= n; i++)
+		factor *= i;
+
+	return factor;
+}
+
+double comb(int n, int r)
+{
+	if(n < r) return 0;
+	return pfat(n, max(r, n - r)) / pfat(min(r, n - r), 0);
+}
+
+double calcScore(string str)
+{
+	return count(str.begin(), str.end(), '+') - count(str.begin(), str.end(), '-');
+}
+
+double calcSpace(string str)
+{
+	return count(str.begin(), str.end(), '?');
+}
+
+double calcPositives(float score, int spaces)
+{
+	return (score + spaces) / 2;
+}
+
+int main()
+{
+	string send, reach;
+	cin >> send >> reach;
+
+	double deltaScore = calcScore(send) - calcScore(reach);
+	double spaces = calcSpace(reach);
+	double positives = calcPositives(deltaScore, spaces);
+	double prob;
+
+	if(spaces > 0 and abs(deltaScore) <= spaces and round(positives) == positives)
+		prob = comb(spaces, positives) * pow(0.5, positives) * pow(0.5, spaces - positives);
+	else
+		prob = !deltaScore ? 1.0f : 0.0f;
+
+
+	printf("%.12f\n", prob);
+	return 0;
+}