Data commit

Task/Percolation-Site-percolation/Zkl/percolation-site-percolation.zkl

@@ -0,0 +1,29 @@
+fcn makeGrid(m,n,p){
+   grid:=Data((m+1)*(n+1));  // first row and right edges are buffers
+   grid.write(" "*m); grid.write("\r");
+   do(n){
+      do(m){ grid.write(((0.0).random(1)<p) and "+" or "."); }  // cell is porous or not
+      grid.write("\n");
+   }
+   grid
+}
+fcn ff(grid,x,m){ // walk across row looking for a porous cell
+   if(grid[x]!=43) return(0); // '+' == 43 ASCII == porous
+   grid[x]="#";
+   return(x+m>=grid.len() or
+	  ff(grid,x+m,m) or ff(grid,x+1,m) or ff(grid,x-1,m) or ff(grid,x-m,m));
+}
+fcn percolate(grid,m){
+   x:=m+1; i:=0; while(i<m and not ff(grid,x,m)){ x+=1; i+=1; }
+   return(i<m);  // percolated through the grid?
+}
+
+grid:=makeGrid(15,15,0.60);
+println("Did liquid percolate: ",percolate(grid,15));
+println("15x15 grid:\n",grid.text);
+
+println("Running 10,000 tests for each case:");
+foreach p in ([0.0 .. 1.0, 0.1]){
+   cnt:=0.0; do(10000){ cnt+=percolate(makeGrid(15,15,p),15); }
+   "p=%.1f:  %.4f".fmt(p, cnt/10000).println();
+}