Submission #56222

#	Time	Username	Problem	Language	Result	Execution time	Memory
56222		youngyojun	Cities (BOI16_cities)	C++11	100 / 100	4038 ms	47504 KiB

cities

#include <bits/stdc++.h>
#define rf(x) (x)=0;while(*p<48)p++;while(47<*p)(x)=((x)<<3)+((x)<<1)+(*p++&15);
#define pb push_back
#define eb emplace_back
#define sz(V) ((int)(V).size())
#define allv(V) ((V).begin()),((V).end())
#define befv(V) ((V)[(sz(V)-2)])
#define sorv(V) sort(allv(V))
#define revv(V) reverse(allv(V))
#define univ(V) (V).erase(unique(allv(V)),(V).end())
#define clv(V) (V).clear()
#define upmin(a,b) (a)=min((a),(b))
#define upmax(a,b) (a)=max((a),(b))
#define rb(x) ((x)&(-(x)))
#define INF (0x3f3f3f3f)
#define INFLL (0x3f3f3f3f3f3f3f3fll)
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, int> pli;
static unsigned char str[22000022], *p=str;
void fg(vector<pii> G[], int a, int b, int c) { G[a].eb(b, c); G[b].eb(a, c); }
const int MAXN = 100005;
const int MAXM = 200005;

vector<pii> G[MAXN];

ll dp[MAXN][1<<5];

int A[MAXM], B[MAXM], C[MAXM];
int D[MAXN];

ll Ans = INFLL;
int N, M, K;

int main() {
	fread(str, 1, 22000022, stdin);
	rf(N) rf(K) rf(M)

	for(int i = 1, c; i <= K; i++) {
		rf(c)
		D[c] = i;
	}
	for(int i = 1; i <= M; i++) {
		rf(A[i]) rf(B[i]) rf(C[i])
		fg(G, A[i], B[i], C[i]);
	}

	for(int i = 1; i <= N; i++)
		fill(dp[i]+1, dp[i]+(1<<K), INFLL);
	
	for(int i = 1; i <= N; i++)
		if(D[i]) dp[i][1<<(D[i]-1)] = 0;

	for(int bi = 1; bi < (1<<K); bi++) {
		for(int i = 1; i <= N; i++)
			for(int key = 0; key <= bi; key++)
				upmin(dp[i][bi], dp[i][key^bi] + dp[i][key]);

		priority_queue<pli, vector<pli>, greater<pli>> PQ;
		for(int i = 1; i <= N; i++) if(dp[i][bi] < INFLL)
			PQ.push(pli(dp[i][bi], i));
		for(; !PQ.empty();) {
			ll dst; int idx;
			tie(dst, idx) = PQ.top(); PQ.pop();
			if(dp[idx][bi] < dst) continue;

			for(auto &e : G[idx]) {
				int nidx = e.first;
				ll ndst = dst + e.second;

				if(dp[nidx][bi] <= ndst) continue;
				dp[nidx][bi] = ndst;
				PQ.push(pli(ndst, nidx));
			}
		}
	}

	for(int i = 1; i <= N; i++)
		upmin(Ans, dp[i][(1<<K)-1]);
	cout << Ans << endl;
	return 0;
}

Compilation message (stderr)

cities.cpp: In function 'int main()':
cities.cpp:37:7: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
  fread(str, 1, 22000022, stdin);
  ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 22 / 22
• Subtask 2: 14 / 14
• Subtask 3: 15 / 15
• Subtask 4: 23 / 23
• Subtask 5: 26 / 26