1 #include <iostream> 2 #include <cstdio> 3 #include <cstring> 4 #include <algorithm> 5 #include <cmath> 6 #define lson l,m,rt<<1 7 #define rson m+1,r,rt<<1|1 8 using namespace std; 9 const int maxn=1111111;10 int sum[maxn<<2];11 int col[maxn<<2];12 void up(int rt){13     sum[rt]=sum[rt<<1]|sum[rt<<1|1];14 }15 void down(int rt){16     if(col[rt]){17         col[rt<<1]=col[rt<<1|1]=col[rt];18         sum[rt<<1]=sum[rt<<1|1]=sum[rt];19         col[rt]=0;20     }21 }22 void build(int l,int r,int rt){23     col[rt]=0;24     sum[rt]=4;25     if(l==r)return;26     int m=(l+r)>>1;27     build(lson);28     build(rson);29     up(rt);30 }31 void update(int L,int R,int c,int l,int r,int rt){32     if(L<=l&&R>=r){33         col[rt]=c;34         sum[rt]=c;35         return;36     }37     down(rt);38     int m=(l+r)>>1;39     if(L<=m)update(L,R,c,lson);40     if(R>m)update(L,R,c,rson);41     up(rt);42 }43 int query(int L,int R,int l,int r,int rt){44     if(L<=l&&R>=r)return sum[rt];45     down(rt);46     int m=(l+r)>>1;47     int ans=0;48     if(L<=m)ans|=query(L,R,lson);49     if(m<R)ans|=query(L,R,rson);50     return ans;51 }52 int main()53 {54 //    freopen("in","r",stdin);55     int n,q;56     while(scanf("%d%d",&n,&q)>0&&(n|q)){57         build(1,n,1);58         char ch[5];59         int a,b,c;60         while(q--){61             scanf("%s",ch);62             if(ch[0]==‘P‘){63                 scanf("%d%d%d",&a,&b,&c);64                 update(a,b,1<<c,1,n,1);65             }66             else {67                 scanf("%d%d",&a,&b);68                 int ans=query(a,b,1,n,1);69                 int fir=0;70                 for(int i=1;i<31;i++){71                     if(ans&(1<<i)){72                         if(fir)printf(" ");73                         printf("%d",i);74                         fir=1;75                     }76                 }77                 puts("");78             }79         }80     }81     return 0;82 }