WA:

for(int i=1;i<=col;i++) if(!du[i]) q.push(i),shu[i]=1,f[i]=num[i];

AC:

for(int i=1;i<=col;i++) if(!du[i]) q.push(i),shu[i]=1,f[i]=num[i],ans1=max(ans1,f[i]);