AtCoder Beginner Contest 190

A Very Very Primitive Game

int main()
{
	int a, b, c;
	cin >> a >> b >> c;
	if(c == 0)
	{
		if(a <= b) puts("Aoki");
		else puts("Takahashi");
	}
	if(c == 1)
	{
		if(b <= a) puts("Takahashi");
		else puts("Aoki");
	}
	return 0;
}

B Magic 3

int main()
{
	int n, s, d;
	scanf("%d%d%d", &n, &s, &d);
	int flag = 0;
	for(int i = 1; i <= n; ++ i)
	{
		int x, y;
		scanf("%d%d", &x, &y);
		if(x < s && y > d) flag = 1;
	}
	puts(flag ? "Yes" : "No");
	return 0;
}

C Bowls and Dishes

int n, m, k;
int a[N], b[N];
int c[N], d[N];
int st[N];
int ans;

void check()
{
	int res = 0;
	for(int i = 1; i <= m; ++ i)
		if(st[a[i]] && st[b[i]]) res ++;
	ans = max(ans, res);
}

void dfs(int t)
{
	if(t == k + 1) check();
	else
	{
		st[d[t]] ++;
		dfs(t + 1);
		st[d[t]] --;
		st[c[t]] ++;
		dfs(t + 1);
		st[c[t]] --;
	}
}

int main()
{
	scanf("%d%d", &n, &m);
	for(int i = 1; i <= m; ++ i) scanf("%d%d", &a[i], &b[i]);
	scanf("%d", &k);
	for(int i = 1; i <= k; ++ i) scanf("%d%d", &c[i], &d[i]);
	dfs(1);
	printf("%d\n", ans);
	return 0;
}

D Staircase Sequences

LL n;

int main()
{
	IOS;
	cin >> n;
	LL res = 0;
	n *= 2;
	for(LL i = 1; i <= n / i; ++ i)
	{
		if(n % i == 0)
		{
			LL a = i, b = n / i;
			if(a % 2 != b % 2) res ++;
		}
	}
	cout << res * 2 << endl;
	return 0;
}

E Magical Ornament

const int N = 2e5 + 10;
const int M = 17;

int n, m, k;
struct Edge
{
	int to, nxt;
}line[N];
int fist[N], idx;
int c[N], d[N];
int f[1 << M][M];
int w[M][M];

void add(int x, int y)
{
	line[idx] = {y, fist[x]};
	fist[x] = idx ++;
}

void bfs(int x)
{
	queue > q;
	q.push({x, 0});
	while(!q.empty())
	{
		auto u = q.front(); q.pop();
		for(int i = fist[u.first]; i != -1; i = line[i].nxt)
		{
			int v = line[i].to;
			if(d[v] == -1)
			{
				d[v] = u.second + 1;
				q.push({v, d[v]});
			}
		}
	}
}

int main()
{
	memset(fist, -1, sizeof fist);
	scanf("%d%d", &n, &m);
	for(int i = 1; i <= m; ++ i)
	{
		int a, b;
		scanf("%d%d", &a, &b);
		add(a, b), add(b, a);
	}
	scanf("%d", &k);
	for(int i = 0; i < k; ++ i) scanf("%d", &c[i]);
	for(int i = 0; i < k; ++ i)
	{
		for(int j = 1; j <= n; ++ j) d[j] = -1;
		d[c[i]] = 0;
		bfs(c[i]);
		for(int j = 0; j < k; ++ j)
			w[i][j] = (d[c[j]] == -1) ? INF : d[c[j]];
	}
	// for(int i = 0; i < k; ++ i)
	// {
	// 	for(int j = 0; j < k; ++ j)
	// 		printf("%d ", w[i][j]);
	// 	puts("");
	// }
	memset(f, 0x3f, sizeof f);
	for(int i = 0; i < k; ++ i) f[1 << i][i] = 1;

	for(int i = 1; i < (1 << k); ++ i)
		for(int j = 0; j < k; ++ j) if(i >> j & 1)
			for(int t = 0; t < k; ++ t) if((i ^ 1 << j) >> t & 1)
				f[i][j] = min(f[i][j], f[i ^ 1 << j][t] + w[t][j]);
	int res = INF;
	for(int i = 0; i < k; ++ i) res = min(res, f[(1 << k) - 1][i]);
	if(res >= INF) puts("-1");
	else printf("%d\n", res);
	return 0;
}

F Shift and Inversions

int n;
int tr[N];
int a[N];

int lowbit(int x) { return x & -x; }
void add(int x, int v) { for(int i = x; i <= n; i += lowbit(i)) tr[i] += v; }
int sum(int x) { int res = 0; for(int i = x; i; i -= lowbit(i)) res += tr[i]; return res; }

int main()
{
	scanf("%d", &n);
	for(int i = 1; i <= n; ++ i) { scanf("%d", &a[i]); a[i] ++; }
	LL res = 0;
	for(int i = 1; i <= n; ++ i)
	{
		res += sum(n) - sum(a[i]);;
		add(a[i], 1);
	}
	printf("%lld\n", res);
	for(int i = 1; i < n; ++ i)
	{
		res -= sum(a[i] - 1);
		res += sum(n) - sum(a[i]);
		printf("%lld\n", res);
	}
	return 0;
}

2021.2.2