Submission #752720

#TimeUsernameProblemLanguageResultExecution timeMemory
752720GrindMachineTug of War (BOI15_tug)C++17
23 / 100
464 ms3304 KiB
// Om Namah Shivaya #include <bits/stdc++.h> #include <ext/pb_ds/assoc_container.hpp> #include <ext/pb_ds/tree_policy.hpp> using namespace std; using namespace __gnu_pbds; template<typename T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>; typedef long long int ll; typedef long double ld; typedef pair<int, int> pii; typedef pair<ll, ll> pll; #define fastio ios_base::sync_with_stdio(false); cin.tie(NULL) #define pb push_back #define endl '\n' #define sz(a) a.size() #define setbits(x) __builtin_popcountll(x) #define ff first #define ss second #define conts continue #define ceil2(x, y) ((x + y - 1) / (y)) #define all(a) a.begin(), a.end() #define rall(a) a.rbegin(), a.rend() #define yes cout << "YES" << endl #define no cout << "NO" << endl #define rep(i, n) for(int i = 0; i < n; ++i) #define rep1(i, n) for(int i = 1; i <= n; ++i) #define rev(i, s, e) for(int i = s; i >= e; --i) #define trav(i, a) for(auto &i : a) template<typename T> void amin(T &a, T b) { a = min(a, b); } template<typename T> void amax(T &a, T b) { a = max(a, b); } #ifdef LOCAL #include "debug.h" #else #define debug(x) 42 #endif /* refs: https://github.com/tmwilliamlin168/CompetitiveProgramming/blob/master/BtOI/15-Tug.cpp https://github.com/nikolapesic2802/Programming-Practice/blob/master/Tug%20of%20War/main.cpp */ const int MOD = 1e9 + 7; const int N = 3e4 + 5; const int inf1 = int(1e9) + 5; const ll inf2 = ll(1e18) + 5; vector<array<ll,3>> adj[N]; void solve(int test_case) { ll n,k; cin >> n >> k; vector<ll> deg(2*n+5); rep1(i,2*n){ ll u,v,w; cin >> u >> v >> w; v += n; adj[u].pb({v,w,i}); adj[v].pb({u,w,i}); deg[u]++, deg[v]++; } queue<ll> q; vector<bool> vis_node(2*n+5), vis_edge(2*n+5); rep1(i,2*n){ if(deg[i] < 2){ q.push(i); } } ll diff = 0; while(!q.empty()){ ll u = q.front(); q.pop(); vis_node[u] = 1; if(!deg[u]){ no; return; } for(auto [v, w, id] : adj[u]){ if(vis_edge[id]) conts; vis_edge[id] = 1; deg[v]--; if(deg[v] < 2){ q.push(v); } if(u <= n) diff += w; else diff -= w; } } rep1(u,2*n){ if(vis_node[u]) conts; vector<array<ll,3>> good; for(auto [v, w, id] : adj[u]){ if(vis_node[v]) conts; good.pb({v,w,id}); } assert(sz(good) == 2); adj[u] = good; } vector<ll> vals; rep1(u,2*n){ if(vis_node[u]) conts; vector<ll> weights; ll ptr = u; ll prev_id = -1; while(true){ if(ptr == u and prev_id != -1){ break; } vis_node[ptr] = 1; for(auto [v, w, id] : adj[ptr]){ if(id == prev_id) conts; weights.pb(w); ptr = v; prev_id = id; break; } } ll val = 0; rep(i,sz(weights)){ ll c = -1; if(!(i & 1)) c = 1; val += c * weights[i]; } val = abs(val); vals.pb(val); } bitset<40*N> dp; dp[20*N] = 1; trav(x,vals){ dp = (dp << x) | (dp >> x); } rep(i,40*N){ if(dp[i]){ ll d = 20*N - i; ll diff2 = diff + d; if(diff2 <= k){ yes; return; } } } no; } int main() { fastio; int t = 1; // cin >> t; rep1(i, t) { solve(i); } return 0; }

Compilation message (stderr)

tug.cpp: In function 'void solve(int)':
tug.cpp:30:36: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   30 | #define rep(i, n) for(int i = 0; i < n; ++i)
      |                                    ^
tug.cpp:154:9: note: in expansion of macro 'rep'
  154 |         rep(i,sz(weights)){
      |         ^~~
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