# | Submission time | Handle | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
931800 | 2024-02-22T11:01:51 Z | LucaIlie | Star Trek (CEOI20_startrek) | C++17 | 1 ms | 4700 KB |
#include <bits/stdc++.h> #define int long long using namespace std; const int MAX_N = 1e5; const int MAX_D = 1e5; const int MOD = 1e9 + 7; bool canWin[MAX_N + 1]; int countChildrenLosers[MAX_N + 1], add[MAX_N + 1], reach[MAX_N + 1], dp[MAX_D][3]; vector<int> adj[MAX_N + 1]; void dfsGame( int u, int p ) { canWin[u] = false; countChildrenLosers[u] = 0; for ( int v: adj[u] ) { if ( v == p ) continue; dfsGame( v, u ); canWin[u] |= (!canWin[v]); countChildrenLosers[u] += (!canWin[v]); } } void dfsCalcAdd( int u, int p ) { if ( p == 0 ) { add[u] = (canWin[u] ? -1 : 1); reach[u] = u; } else { if ( canWin[u] ) { if ( canWin[p] ) { add[u] = -1; reach[u] = u; } else { add[u] = add[p] - 1; reach[u] = reach[p]; } } else { if ( countChildrenLosers[p] >= 2 ) { add[u] = 1; reach[u] = u; } else { add[u] = add[p] + 1; reach[u] = reach[p]; } } } for ( int v: adj[u] ) { if ( v == p ) continue; dfsCalcAdd( v, u ); } } int lgPut( int x, int n ) { if ( n == 0 ) return 1; int p = lgPut( x, n / 2 ); p = (long long)p * p % MOD; if ( n % 2 == 1 ) p = (long long)p * x % MOD; return p; } signed main() { int n, d; cin >> n >> d; for ( int i = 0; i < n - 1; i++ ) { int u, v; cin >> u >> v; adj[u].push_back( v ); adj[v].push_back( u ); } cout << lgPut( 4, d ) << "\n"; return 0; int pom = 0; int winners = 0; for ( int v = 1; v <= n; v++ ) { dfsGame( v, 0 ); winners += canWin[v]; int w = 0; for ( int u = 1; u <= n; u++ ) w += canWin[u]; if (pom == 0) pom = w; if ( pom != w ) exit( 1 ); } dfsGame( 1, 0 ); dfsCalcAdd( 1, 0 ); int countAdd1 = 0; for ( int v = 1; v <= n; v++ ) countAdd1 += (add[v] == 1); dp[0][0] = 1; for ( int i = 1; i < d; i++ ) { for ( int a = 0; a < 2; a++ ) { int add1 = countAdd1 * (n - (winners + a)) % MOD; int add0 = (n * n - add1) % MOD; dp[i][0] = (dp[i][0] + dp[i - 1][a] * add0) % MOD; dp[i][1] = (dp[i][1] + dp[i - 1][a] * add1) % MOD; } printf( "%d %d\n", dp[i][0], dp[i][1] ); } int ans = 0; for ( int a = 0; a < 2; a++ ) { for ( int v = 1; v <= n; v++ ) { if ( canWin[1] ) { if ( canWin[v] ) ans = (ans + n * dp[d - 1][a]) % MOD; else { ans = (ans + (winners + a) * dp[d - 1][a]) % MOD; if ( reach[v] != 1 ) ans = (ans + (n - winners - a) * dp[d - 1][a]) % MOD; } } else { if ( !canWin[v] ) { if ( reach[v] == 1 ) ans = (ans + (n - winners - a) * dp[d - 1][a]) % MOD; } } } } cout << ans << "\n"; return 0; }
Compilation message
# | Verdict | Execution time | Memory | Grader output |
---|---|---|---|---|
1 | Correct | 1 ms | 4700 KB | Output is correct |
2 | Incorrect | 1 ms | 4700 KB | Output isn't correct |
3 | Halted | 0 ms | 0 KB | - |
# | Verdict | Execution time | Memory | Grader output |
---|---|---|---|---|
1 | Correct | 1 ms | 4700 KB | Output is correct |
2 | Correct | 1 ms | 4700 KB | Output is correct |
3 | Correct | 1 ms | 4700 KB | Output is correct |
4 | Correct | 1 ms | 4700 KB | Output is correct |
5 | Correct | 1 ms | 4700 KB | Output is correct |
# | Verdict | Execution time | Memory | Grader output |
---|---|---|---|---|
1 | Correct | 1 ms | 4700 KB | Output is correct |
2 | Incorrect | 1 ms | 4700 KB | Output isn't correct |
3 | Halted | 0 ms | 0 KB | - |
# | Verdict | Execution time | Memory | Grader output |
---|---|---|---|---|
1 | Correct | 1 ms | 4700 KB | Output is correct |
2 | Incorrect | 1 ms | 4700 KB | Output isn't correct |
3 | Halted | 0 ms | 0 KB | - |
# | Verdict | Execution time | Memory | Grader output |
---|---|---|---|---|
1 | Correct | 1 ms | 4700 KB | Output is correct |
2 | Incorrect | 1 ms | 4700 KB | Output isn't correct |
3 | Halted | 0 ms | 0 KB | - |
# | Verdict | Execution time | Memory | Grader output |
---|---|---|---|---|
1 | Correct | 1 ms | 4700 KB | Output is correct |
2 | Incorrect | 1 ms | 4700 KB | Output isn't correct |
3 | Halted | 0 ms | 0 KB | - |
# | Verdict | Execution time | Memory | Grader output |
---|---|---|---|---|
1 | Correct | 1 ms | 4700 KB | Output is correct |
2 | Incorrect | 1 ms | 4700 KB | Output isn't correct |
3 | Halted | 0 ms | 0 KB | - |
# | Verdict | Execution time | Memory | Grader output |
---|---|---|---|---|
1 | Correct | 1 ms | 4700 KB | Output is correct |
2 | Incorrect | 1 ms | 4700 KB | Output isn't correct |
3 | Halted | 0 ms | 0 KB | - |