CodeforcesRound#263(Div.1)ABC_html/css

#include #include #include #include #include using namespace std;typedef long long ll;const int N = 300005;int n;ll a[N], sum[N];int main() {	scanf("%d", &n);ll ans = 0; 	for (int i = 0; i < n; i++) {	 	scanf("%lld", &a[i]);	 ans += a[i];	}	sort(a, a + n);	for (int i = n - 1; i >= 0; i--)	sum[i] = a[i] + sum[i + 1];	for (int i = 0; i < n - 1; i++) {	ans += sum[i];	}	printf("%lld\n", ans);	//system("pause");	return 0;}

#include #include #include #include using namespace std;const int N = 100005;typedef long long ll;const ll MOD = 1000000007;int n, node[N];vector g[N];ll dp[N][2];ll pow_mod(ll x, ll k) { ll ans = 1; while (k) { if (k&1) ans = ans * x % MOD; x = x * x % MOD; k >>= 1; } return ans;}ll inv(ll x) { return pow_mod(x, MOD - 2);}void init() { scanf("%d", &n); int u; for (int i = 1; i < n; i++) { scanf("%d", &u); g[u].push_back(i); } for (int i = 0; i < n; i++) scanf("%d", &node[i]);}void dfs(int u) { if (g[u].size() == 0) { dp[u][node[u]] = 1; return; } for (int i = 0; i < g[u].size(); i++) dfs(g[u][i]); dp[u][0] = dp[u][1] = 1; if (node[u]) { dp[u][0] = 0; for (int i = 0; i < g[u].size(); i++) { int v = g[u][i]; dp[u][1] = dp[u][1] * (dp[v][0] + dp[v][1]) % MOD; } } else { ll cnt = 0; ll mul = 1; for (int i = 0; i < g[u].size(); i++) { int v = g[u][i]; dp[u][0] = dp[u][0] * (dp[v][0] + dp[v][1]) % MOD; mul = mul * (dp[v][0] + dp[v][1]) % MOD; } dp[u][1] = 0; for (int i = 0; i < g[u].size(); i++){ int v = g[u][i]; dp[u][1] = (dp[u][1] + mul * inv((dp[v][0] + dp[v][1]) % MOD) % MOD * dp[v][1]) % MOD; } }}int main() { init(); dfs(0); printf("%lld\n", dp[0][1] % MOD); //system("pause"); return 0;}

#include #include #include using namespace std;#define lowbit(x) (x&(-x))const int N = 100005;int n, q, bit[N];void add(int x, int v) { while (x < N) { bit[x] += v; x += lowbit(x); }}int get(int x) { int ans = 0; while (x) { ans += bit[x]; x -= lowbit(x); } return ans;}int main() { scanf("%d%d", &n, &q); for (int i = 1; i <= n; i++) add(i, 1); int tp, a, b; int l = 1, r = n, flip = 0; while (q--) { scanf("%d%d", &tp, &a); if (tp == 1) { int tl = l, tr = r; if (a <= (r - l + 1) / 2) { if (flip) { for (int i = a; i >= 1; i--) { add(r - 2 * i + 1, get(tr - a + i) - get(tr - a + i - 1)); r--; } } else { for (int i = a; i >= 1; i--) { add(l + 2 * i - 1, get(tl + a - i) - get(tl + a - i - 1)); l++; } } } else { a = r - a - l + 1; if (!flip) { for (int i = a; i >= 1; i--) { add(r - 2 * i + 1, get(tr - a + i) - get(tr - a + i - 1)); r--; } } else { for (int i = a; i >= 1; i--) { add(l + 2 * i - 1, get(tl + a - i) - get(tl + a - i - 1)); l++; } } flip ^= 1; } } else { scanf("%d", &b); if (flip) { a = r - a; b = r - b; swap(a, b); } else { a += l - 1; b += l - 1; } printf("%d\n", get(b) - get(a)); } } return 0;}