The number of colors in the graph

Purple book P286:

Classic problem, no graph G, each node staining, adjacent nodes of different colors, to find the minimum number of colors.

Set D (s) to indicate the minimum color required to dye the node S. Then there is D (S) = d (s-s ') + 1; S ' is a color that can be dyed, (i.e. s ' no u,v makes u,v adjacent). The subset S ' is then enumerated in S.

#include <bits/stdc++.h>using namespacestd;#defineMaxnode 1000#defineINF 0x3f3f3f3fintN///Number of nodesintd[maxnode<<1]intMain () {d[0] =0;  for(ints=1; s< (1&LT;&LT;N); s++) {D[s]=INF;  for(intS0 = S; S0; S0 = (s0-1) &S) {if(No_edges_inside[s0]) D[s]= Min (d[s],d[s-s0]+1); }    }            return 0;}

The number of colors in the graph