Solve problems 227A, 227B and 227C from codeforces

Author: AliOsm

CodeForces/227A. Where do I Turn?.cpp

@@ -0,0 +1,20 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+int main() {
+	int ax, ay, bx, by, cx, cy;
+	scanf("%d %d %d %d %d %d", &ax, &ay, &bx, &by, &cx, &cy);
+
+	if((1ll * (by - ay) * (cx - bx)) == (1ll * (cy - by) * (bx - ax)))
+		puts("TOWARDS");
+	else {
+		long long v = (1ll * (bx - ax) * (cy - ay)) - (1ll * (cx - ax) * (by - ay));
+		if(v > 0)
+			puts("LEFT");
+		else
+			puts("RIGHT");
+	}
+
+	return 0;
+}

CodeForces/227B. Effective Approach.cpp

@@ -0,0 +1,28 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+int const N = 1e5 + 1;
+int n, q, a[N];
+vector<int> idx[N];
+
+int main() {
+	scanf("%d", &n);
+	for(int i = 0; i < n; ++i) {
+		scanf("%d", a + i);
+		idx[a[i]].push_back(i + 1);
+	}
+
+	scanf("%d", &q);
+	int tmp;
+	long long l = 0, r = 0;
+	while(q-- != 0) {
+		scanf("%d", &tmp);
+		l += idx[tmp].front();
+		r += n - idx[tmp].back() + 1;
+	}
+
+	printf("%lld %lld\n", l, r);
+
+	return 0;
+}

CodeForces/227C. Flying Saucer Segments.cpp

@@ -0,0 +1,30 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+int n, m;
+
+long long power(long long a, int p) {
+	if(p == 0)
+		return 1;
+
+	long long res = power(a, p >> 1) % m;
+	res = (res * res) % m;
+
+	if(p & 1)
+		res = (res * a) % m;
+
+	return res;
+}
+
+int main() {
+	scanf("%d %d", &n, &m);
+
+	long long lst = power(3, n) - 1;
+	if(lst >= 0)
+		printf("%lld\n", lst);
+	else
+		printf("%lld\n", lst + m);
+
+	return 0;
+}

CodeForces/README.md

@@ -55,6 +55,9 @@
 - [200B. Drinks](http://codeforces.com/problemset/problem/200/B)
 - [208A. Dubstep](http://codeforces.com/problemset/problem/208/A)
 - [214A. System of Equations](http://codeforces.com/problemset/problem/214/A)
+- [227A. Where do I Turn?](http://codeforces.com/contest/227/problem/A)
+- [227B. Effective Approach](http://codeforces.com/contest/227/problem/B)
+- [227C. Flying Saucer Segments](http://codeforces.com/contest/227/problem/C)
 - [230A. Dragons](http://codeforces.com/problemset/problem/230/A)
 - [230B. T-primes](http://codeforces.com/problemset/problem/230/B)
 - [231A. Team](http://codeforces.com/problemset/problem/231/A)