stuff

.gitignore

@@ -1,3 +1,4 @@
 .vscode/ipch
 a.exe
+a.out
 .history

Olympiad Practise/week 33/.cph/.devices.cpp_34c4d36b6961736ac993b19519f39e27.prob

@@ -0,0 +1 @@
+{"name":"Local: devices","url":"f:\\GitHub\\Practice\\Olympiad Practise\\week 33\\devices.cpp","tests":[{"id":1616872340528,"input":"5\n1 2 3 2 1\n1\n3","output":"2"},{"id":1616872753362,"input":"5\n1 2 5 5 4\n4\n1\n5\n3\n4","output":"1\n1\n1\n2"}],"interactive":false,"memoryLimit":1024,"timeLimit":3000,"srcPath":"f:\\GitHub\\Practice\\Olympiad Practise\\week 33\\devices.cpp","group":"local","local":true}

Olympiad Practise/week 33/.cph/.orzbruce4.cpp_c3c7c2a1162e6e9d5e078c585272eaf9.prob

@@ -0,0 +1 @@
+{"name":"Local: orzbruce4","url":"f:\\GitHub\\Practice\\Olympiad Practise\\week 33\\orzbruce4.cpp","tests":[{"id":1616870541020,"input":"4 4 1\n1 4\n1 2\n1 3\n4 2","output":"2"},{"id":1616870546543,"input":"10 6 2\n1 2\n2 10\n4 8\n8 10\n5 7\n2 4","output":"4"}],"interactive":false,"memoryLimit":1024,"timeLimit":3000,"srcPath":"f:\\GitHub\\Practice\\Olympiad Practise\\week 33\\orzbruce4.cpp","group":"local","local":true}

Olympiad Practise/week 33/devices.cpp

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+#include <bits/stdc++.h>
+using namespace std;
+typedef long long ll;
+typedef unsigned long long ull;
+typedef long double ld;
+typedef pair<int, int> pi;
+typedef pair<ll, int> pli;
+typedef pair<int, ll> pil;
+typedef pair<ll, ll> pl;
+typedef pair<ld, ld> pd;
+
+typedef vector<int> vi;
+typedef vector<ld> vd;
+typedef vector<ll> vl;
+typedef vector<pi> vpi;
+typedef vector<pl> vpl;
+
+#define INF 0x3f3f3f3f            // for int
+#define LL_INF 0x3f3f3f3f3f3f3f3f // for ll
+#define sz(x) (int)(x).size()
+#define ms(x, y) memset(x, y, sizeof(x))
+#define mp make_pair
+#define pb push_back
+#define lb lower_bound
+#define ub upper_bound
+#define all(x) x.begin(), x.end()
+#define ins insert
+
+const int MOD = 1000000007, MX = 100000 + 5;
+
+int N, A[MX], D;
+int freq[MX];
+
+ll f[MX]; //factorial
+ll inv[MX];
+
+//quick power
+ll quickpow(ll base, ll exp)
+{
+  ll ans = 1;
+  for (base %= MOD; exp; exp >>= 1, base = (base * base) % MOD)
+    if (exp & 1)
+      ans = (ans * base) % MOD;
+  return ans;
+}
+
+//nChoosek nck choosing notation
+ll choose(int n, int k)
+{
+  return f[n] * inv[k] % MOD * inv[n - k] % MOD;
+}
+
+//initializing choosing notation and factorial etc
+void init(int N)
+{
+  f[0] = 1;
+  inv[0] = 1;
+  for (int i = 1; i <= N + 5; i++)
+    f[i] = f[i - 1] * i % MOD;
+  for (int i = 1; i <= N + 5; i++)
+    inv[i] = quickpow(f[i], MOD - 2);
+}
+
+int main()
+{
+  scanf("%d", &N);
+  init(N);
+
+  for (int i = 1; i <= N; i++)
+  {
+    scanf("%d", A + i);
+    freq[A[i]]++;
+  }
+  sort(A + 1, A + 1 + N);
+  for (int i = 1; i <= N; i++)
+    freq[i] += freq[i - 1];
+
+  scanf("%d", &D);
+  for (int i = 1, k; i <= D; i++)
+  {
+    scanf("%d", &k);
+    int p = A[k];
+    int need = k - freq[p - 1], tot = freq[p] - freq[p - 1];
+    printf("%lld\n", choose(tot, need));
+  }
+
+  return 0;
+}

Olympiad Practise/week 33/orzbruce4.cpp

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+#include <bits/stdc++.h>
+using namespace std;
+typedef long long ll;
+typedef unsigned long long ull;
+typedef long double ld;
+typedef pair<int, int> pi;
+typedef pair<ll, int> pli;
+typedef pair<int, ll> pil;
+typedef pair<ll, ll> pl;
+typedef pair<ld, ld> pd;
+
+typedef vector<int> vi;
+typedef vector<ld> vd;
+typedef vector<ll> vl;
+typedef vector<pi> vpi;
+typedef vector<pl> vpl;
+
+#define INF 0x3f3f3f3f            // for int
+#define LL_INF 0x3f3f3f3f3f3f3f3f // for ll
+#define sz(x) (int)(x).size()
+#define ms(x, y) memset(x, y, sizeof(x))
+#define mp make_pair
+#define pb push_back
+#define f first
+#define s second
+#define lb lower_bound
+#define ub upper_bound
+#define all(x) x.begin(), x.end()
+#define ins insert
+
+const int MOD = 1000000007, MX = 200000 + 5;
+
+int N, M, K;
+vector<int> G[MX];
+int dist1[MX], distN[MX];
+
+//quick power
+ll quickpow(ll base, ll exp)
+{
+  ll ans = 1;
+  for (base %= MOD; exp; exp >>= 1, base = (base * base) % MOD)
+    if (exp & 1)
+      ans = (ans * base) % MOD;
+  return ans;
+}
+
+int main()
+{
+  scanf("%d %d %d", &N, &M, &K);
+  for (int i = 1, a, b; i <= M; i++)
+  {
+    scanf("%d %d", &a, &b);
+    G[a].push_back(b);
+    G[b].push_back(a);
+  }
+
+  queue<pi> q;
+  q.push({1,0});
+  dist1[1]=-1;
+  while(!q.empty()){
+    for(int n : G[q.front().f]){
+      if(dist1[n])continue;
+      dist1[n] = q.front().s+1;
+      q.push({n, dist1[n]});
+    }
+    q.pop();
+  }
+
+  q.push({N,0});
+  distN[N]=-1;
+  while(!q.empty()){
+    for(int n : G[q.front().f]){
+      if(distN[n])continue;
+      distN[n] = q.front().s+1;
+      q.push({n, distN[n]});
+    }
+    q.pop();
+  }
+
+  ll num = 0;
+
+  for(int i = 1; i <= N; i++)
+  {
+    // printf("%d: %d %d\n", i, dist1[i], distN[i]);
+    if(dist1[i]<=0 || distN[i] <= 0)continue;
+    // printf("yes\n");
+    if(dist1[i] <= K && distN[i] <= K)num++;
+  }
+
+
+  printf("%lld\n", quickpow(2, num));
+  return 0;
+}