Uoj 176 New Year's boom-greedy-Query

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Each vertex has a vertex weight $ a_ I $. The Edge Weight of the edge of $ U $ and the vertex $ V $ is $ a_u \ and \ a_v $. Ask the maximum spanning tree.

We consider each edge weight from the largest to the smallest. If the vertex weights of Two unconnected points simultaneously contain this edge weight as a subset, it is obvious that such edges are used to connect these points to the optimum.

Therefore, we use and query sets to retrieve a token for each edge weight that has been considered.

Each time a new edge weight is enumerated, some existing connected blocks are merged.

Code

 1 /** 2  * uoj 3  * Problem#176 4  * Accepted 5  * Time: 1128ms 6  * Memory: 3276k 7  */ 8 #include <iostream> 9 #include <cstdlib>10 #include <cstdio>11 #ifndef WIN3212 #define Auto "%lld"13 #else14 #define Auto "%I64d"15 #endif16 using namespace std;17 typedef bool boolean;18 19 #define ll long long20 21 template <typename T>22 void pfill(T* pst, const T* ped, T val) {23     for ( ; pst != ped; *(pst++) = val);24 }25 26 int n, m;27 int S;28 int *f, *ar;29 ll res = 0;30 31 int find(int x) {32     return (f[x] == x) ? (x) : (f[x] = find(f[x]));33 }34 35 inline void init() {36     scanf("%d%d", &n, &m);37     S = 1 << m;38     f = new int[S];39     ar = new int[S];40     pfill(ar, ar + S, 0);41     for (int i = 1, x; i <= n; i++) {42         scanf("%d", &x);43         if (!ar[x])44             f[x] = x, ar[x] = x;45         else46             res += x;47     }48 }49 50 inline void solve() {51     for (int s = S - 1, x, y; s; s--) {52         for (int i = 0; !ar[s] && i < m; ar[s] |= ar[s | (1 << (i++))]);53         if (!(x = ar[s]))54             continue;55         for (int i = 0; i < m; i++)56             if (ar[s | (1 << i)]) {57                 y = find(ar[s | (1 << i)]);58                 if (y ^ find(x)) {59                     f[y] = find(x), ar[s] = find(x);60                     res += s;61                 }62             }63     }64     printf(Auto, res);65 }66 67 int main() {68     init();69     solve();70     return 0;71 }

Uoj 176 New Year's boom-greedy-Query