HDU 4085 Peach Blossom Spring eectilinear State compression DP+SPFA

State compression DP+SPFA Chestan Nashu

Enumeration subtree morphology dp[i][j] = min (Dp[i][j], dp[i][k]+dp[i][l]) where K and L are a division of J

relax by the edge dp[i][j] = min (dp[i][j], dp[i '][j]+w[i][j]) where I and I ' have an edge connected

#include <cstdio> #include <cstring> #include <queue>using namespace std;const int maxn = 55;const int ma XM = 1010;const int INF = 9999999;int N, m, K;int D[maxn][maxn];int DP[1&LT;&LT;16][MAXN], dp2[1<<16], a[1<<16 ];int Inq[1<<16][maxn];int FIRST[MAXN], cnt;struct Node{int V, W, next;} E[2222];struct edge{int u, V, W;edge () {}edge (int u, int v, int w): U (U), V (v), W (w) {}};queue <edge> q;void SPFA () {W Hile (! Q.empty ()) {Edge x = Q.front (); Q.pop (); int u = x.u, v = x.v;inq[u][v] = 0;for (int i = 0; i < n; i++) {if (d[v][i]! =-1) {if (Dp[u|a[i]][i] > Dp[u][v] + D[v][i]) {dp[u|a[i]][i] = Dp[u][v] + d[v][i];if (!inq[u|a[i]][i] && (u|a[i]) = = u) {inq[u|a[i]][i] = 1; Q.push (Edge (U|a[i], I, dp[u|a[i]][i]));}}}}    bool OK (int x) {int ans = 0;    for (int i = 0; x; i++, x >>= 1) ans + = (x&1) * (I < K 1:-1); return ans = = 0;} void Floyd () {for (int l = 0, l < n; l++) for (int i = 0, i < n; i++) for (int j = 0; J < N; j + +) if (d[I][L]! =-1 && d[l][j]! =-1) if (d[i][j] = = 1 | | d[i][j] > D[I][L]+D[L][J]) d[i][j] = D[i][l]+d[l][j];} void Steiner () {int all = (1<< (2*k)), for (int i = 0, i < all, i++) for (int j = 0; J < N; j + +) Dp[i][j] = Inf;memse T (A, 0, sizeof (a)); for (int i = 0; i < K; i++) a[i] = (1<<i), dp[(1<<i)][i] = 0;for (int i = k; i < 2*k; i+ +) A[n-2*k+i] = (1<<i), dp[(1<<i)][n-2*k+i] = 0;for (int s = 1; s < all; s++) {for (int i = 0; i < n; i++) {f or (int s0 = (s-1) &s; s0; s0 = (s0-1) &s) {Dp[s][i] = min (Dp[s][i], dp[s0|a[i]][i]+dp[(S^S0) |a[i]][i]);} if (Dp[s][i] < INF) {Q.push (Edge (S, I, dp[s][i])); inq[s][i] = 1;}} SPFA ();} for (int i = 0; i < all; i++) {Dp2[i] = inf;for (int j = 0; J < N; j + +) Dp2[i] = min (Dp2[i], dp[i][j]);} for (int i = 1; i < all; i++) {if (ok (i)) {(int s = (i-1) &i; s; s = (s-1) &i) {if (ok (i^s)) dp2[i] = min (dp2[i), DP2 [S]+dp2[i^s]);}}} if (dp2[all-1] = = INF) puts ("No solution"); elseprintf ("%d\n", Dp2[all-1]);} int main () {int t;sCANF ("%d", &t), while (t--) {scanf ("%d%d%d", &n, &m, &k), memset (d,-1, sizeof (d)), and for (int i = 0; i < m;  i++) {int x, Y, z;scanf ("%d%d%d", &x, &y, &z), x--, y--;if (d[x][y] = = 1 | | d[x][y] > z) d[x][y] = d[y][x] = Z;} Floyd (); Steiner ();} return 0;}

HDU 4085 Peach Blossom Spring eectilinear State compression DP+SPFA