1 files changed, 144 insertions, 0 deletions
diff --git a/common.h b/common.h
new file mode 100644
index 0000000..2597c41
--- /dev/null
+++ b/common.h
@@ -0,0 +1,144 @@
+#include <iostream>
+#include <iomanip>
+#include <vector>
+#include <cstring>
+#include <cstdlib>
+#include <cassert>
+
+using namespace std;
+
+const int NPLAYERS=2;
+const int WID=7,HEI=8;
+
+
+template <typename T>
+ostream& operator<<(ostream &os,const vector<T> &v){
+	const int sz=v.size();
+	if(sz==0)return os;
+	os<<v[0];
+	for(int i=1;i<sz;i++)os<<' '<<v[i];
+	return os;
+}
+
+
+struct Move{
+	int x,y;
+
+	Move(void):x(-1),y(-1){}
+	Move(int idx):x(idx%WID),y(idx/WID){}
+	Move(int _x,int _y):x(_x),y(_y){}
+
+	int idx(void){return WID*y+x;}
+};
+
+class Board{
+	int balls[WID*HEI],colour[WID*HEI];
+	int wonby=-1; //kept up-to-date by stabilise()
+	int nballs=0;
+
+public:
+	inline Board(void){
+		memset(balls,0,WID*HEI*sizeof(int));
+		memset(colour,0,WID*HEI*sizeof(int));
+	}
+	inline Board(const Board &other):wonby(other.wonby){
+		memcpy(balls,other.balls,WID*HEI*sizeof(int));
+		memcpy(colour,other.colour,WID*HEI*sizeof(int));
+	}
+
+	inline int getballs(int idx){return balls[idx];}
+	inline int getballs(int x,int y){return getballs(WID*y+x);}
+	inline int getcolour(int idx){return colour[idx];}
+	inline int getcolour(int x,int y){return getcolour(WID*y+x);}
+
+	inline bool put(int x,int y,int c){
+		const int idx=WID*y+x;
+		if(balls[idx]&&colour[idx]!=c)return false;
+		balls[idx]++;
+		colour[idx]=c;
+		nballs++;
+		stabilise();
+		return true;
+	}
+	inline bool put(int idx,int c){return put(idx%WID,idx/WID,c);}
+
+	inline bool putq(int idx,int c) const{return !balls[idx]||colour[idx]==c;}
+	inline bool putq(int x,int y,int c) const{return putq(WID*y+x,c);}
+
+	inline void stabilise(void){
+		int nballs[WID*HEI],ncolour[WID*HEI]; //new values
+		bool changed;
+		int x,y;
+		do {
+			changed=false;
+			memcpy(nballs,balls,WID*HEI*sizeof(int));
+			memcpy(ncolour,colour,WID*HEI*sizeof(int));
+
+			for(y=0;y<HEI;y++)for(x=0;x<WID;x++){
+				const int idx=WID*y+x;
+				const int nnei=(y>0)+(x>0)+(y<HEI-1)+(x<WID-1);
+				if(balls[idx]>=nnei){
+					const int quo=balls[idx]/nnei;
+					nballs[idx]-=nnei*quo;
+					if(y>0){nballs[idx-WID]+=quo;ncolour[idx-WID]=colour[idx];}
+					if(x>0){nballs[idx-1]+=quo;ncolour[idx-1]=colour[idx];}
+					if(y<HEI-1){nballs[idx+WID]+=quo;ncolour[idx+WID]=colour[idx];}
+					if(x<WID-1){nballs[idx+1]+=quo;ncolour[idx+1]=colour[idx];}
+					changed=true;
+				}
+			}
+			wonby=-1;
+			for(int i=0;i<WID*HEI;i++){
+				if(nballs[i]==0)continue;
+				if(wonby==-1)wonby=ncolour[i];
+				else if(wonby!=ncolour[i]){
+					wonby=-1;
+					break;
+				}
+			}
+
+			memcpy(balls,nballs,WID*HEI*sizeof(int));
+			memcpy(colour,ncolour,WID*HEI*sizeof(int));
+		} while(changed&&wonby==-1);
+	}
+
+	//returns -1 for no win yet, >=0 for that colour
+	inline int checkwin(void) const{return wonby;}
+
+	inline int ballcount(int c) const{
+		int i,count=0;
+		for(i=0;i<WID*HEI;i++){
+			count+=balls[i]*(colour[i]==c);
+		}
+		return count;
+	}
+
+	inline int totalballcount(void) const{return nballs;}
+
+	void print(ostream &os){
+		int x,y;
+		for(y=0;y<HEI;y++){
+			for(x=0;x<WID;x++){
+				if(balls[WID*y+x]){
+					os<<"\x1B[3"<<colour[WID*y+x]+1<<'m'<<setw(2)<<balls[WID*y+x]<<"\x1B[0m ";
+				} else os<<".. ";
+			}
+			os<<endl;
+		}
+	}
+};
+
+Move randommove(const Board &bd,int c){
+	Move poss[WID*HEI];
+	int nposs=0;
+	int i;
+	for(i=0;i<WID*HEI;i++){
+		if(bd.putq(i,c)){
+			poss[nposs].x=i%WID;
+			poss[nposs].y=i/WID;
+			nposs++;
+		}
+	}
+	if(nposs==0)return Move();
+	return poss[rand()%nposs];
+}