又写错了...
if (t<=9876 && !used[t%10] && !used[t/10%10] && !used[t/100%10] && !used[t/1000%10])
才对。最近我怎么很模糊啊...
if (t<=9876 && !used[t%10] && !used[t/10%10] && !used[t/100%10] && !used[t/1000%10])
才对。最近我怎么很模糊啊...
Have you visit acm.tongji. lately?