runs=100000 a=rep(0,runs) for (i in 1:runs) { track=rep('O',2) count=0;finished=FALSE while (finished==FALSE) { count=count+1 r=runif(1) track[1]=track[2]; if (r<1/2) {track[2]='H'} else {track[2]='T'} if ((track[1]=='T') && (track[2]=='H')) {finished=TRUE} } a[i]=count } mean(a) a=rep(0,runs) for (i in 1:runs) { track=rep('O',2) count=0;finished=FALSE while (finished==FALSE) { count=count+1 r=runif(1) track[1]=track[2]; if (r<1/2) {track[2]='H'} else {track[2]='T'} if ((track[1]=='H') && (track[2]=='H')) {finished=TRUE} } a[i]=count } mean(a)