洛谷3384

  1 #include<cstdio>
  2 #include<algorithm>
  3 #define ls (cur<<1)
  4 #define rs (cur<<1|1)
  5 #define len(x) (a[x].r-a[x].l+1)
  6 #define mid ((a[cur].l+a[cur].r)>>1) 
  7 using namespace std;
  8 const int maxn=500010;
  9 int n,m,Mod,k,x,y,z,root,tot=0,num=0;
 
 10 int v[maxn],pos[maxn],dfn[maxn],dep[maxn],son[maxn],size[maxn],fa[maxn],top[maxn],last[maxn];
 11 struct edge{int to,pre;}e[maxn];
 12 struct tree{int l,r,sum,del;}a[maxn<<2];
 13 inline void read(int &k){
 14     k=0; int f=1; char c=getchar();
 15     while(c<‘0‘||c>‘9‘)c==‘-‘&&(f=-1
 
),c=getchar();
 16     while(‘0‘<=c&&c<=‘9‘)k=k*10+c-‘0‘,c=getchar();
 17     k*=f;
 18 }
 19 inline void MOD(int &k){if (k>=Mod) k-=Mod;}
 20 inline void add(int x,int y){e[++tot].to=y; e[tot].pre=last[x]; last[x]=tot;}
 21 void dfs1(int x){
 22     size[x]=1; dep[x]=dep[fa[x]]+1;
 
 23     for (int i=last[x],to;i;i=e[i].pre)
 24     if ((to=e[i].to)!=fa[x]){
 25         fa[to]=x; dfs1(to);
 26         size[x]+=size[to];
 27         if (size[to]>size[son[x]]) son[x]=to;
 28     }
 29 }
 30 void dfs2(int x,int tp){
 31     top[x]=tp; dfn[x]=++num; pos[num]=x;
 32     if (son[x]) dfs2(son[x],tp);
 33     for (int i=last[x],to;i;i=e[i].pre)
 34     if ((to=e[i].to)!=fa[x]&&to!=son[x]) dfs2(to,to);
 35 }
 36 void build(int cur,int l,int r){
 37     a[cur].l=l; a[cur].r=r;
 38     if (l<r){
 39         build(ls,l,mid); build(rs,mid+1,r);
 40         a[cur].sum=a[ls].sum+a[rs].sum,MOD(a[cur].sum);
 41     }
 42     else a[cur].sum=v[pos[l]];
 43 }
 44 void pushdown(int cur){
 45     if (a[cur].del==0) return; int D=a[cur].del;
 46     a[ls].del+=D;MOD(a[ls].del); a[ls].sum=(a[ls].sum+len(ls)*D)%Mod;
 47     a[rs].del+=D;MOD(a[rs].del); a[rs].sum=(a[rs].sum+len(rs)*D)%Mod;
 48     a[cur].del=0;
 49 }
 50 void add(int cur,int l,int r,int delta){
 51     if (l<=a[cur].l&&a[cur].r<=r){
 52         a[cur].del=(a[cur].del+delta)%Mod;
 53         a[cur].sum=(a[cur].sum+len(cur)*delta)%Mod; return;  
 54     }
 55     pushdown(cur);
 56     if (l<=mid) add(ls,l,r,delta);
 57     if (r>mid) add(rs,l,r,delta);
 58     a[cur].sum=a[ls].sum+a[rs].sum; MOD(a[cur].sum);
 59 }
 60 int query(int cur,int l,int r){
 61     if (l<=a[cur].l&&a[cur].r<=r) return a[cur].sum;
 62     pushdown(cur); int ret=0;
 63     if (l<=mid) ret+=query(ls,l,r),MOD(ret); 
 64     if (r>mid) ret+=query(rs,l,r),MOD(ret);
 65     return ret;
 66 }
 67 int main(){
 68     read(n); read(m); read(root); read(Mod);
 69     for (int i=1;i<=n;i++) read(v[i]),v[i]%=Mod;
 70     for (int i=1;i<n;i++) read(x),read(y),add(x,y),add(y,x);
 71     dfs1(root); dfs2(root,root); build(1,1,n);
 72     for (int i=1;i<=m;i++){
 73         read(k);
 74         if (k==1){
 75             read(x); read(y); read(z);
 76             while(top[x]!=top[y]){
 77                 if (dep[top[x]]<dep[top[y]]) swap(x,y);
 78                 add(1,dfn[top[x]],dfn[x],z); x=fa[top[x]];
 79             }
 80             if (dep[x]>dep[y]) swap(x,y);
 81             add(1,dfn[x],dfn[y],z);
 82         }
 83         if (k==2){
 84             read(x); read(y); int ans=0;
 85             while(top[x]!=top[y]){
 86                 if (dep[top[x]]<dep[top[y]]) swap(x,y);
 87                 ans+=query(1,dfn[top[x]],dfn[x]); MOD(ans); x=fa[top[x]];
 88             }
 89             if (dep[x]>dep[y]) swap(x,y); ans+=query(1,dfn[x],dfn[y]); MOD(ans);
 90             printf("%d\n",ans);
 91         } 
 92         if (k==3){
 93             read(x); read(y);
 94             add(1,dfn[x],dfn[x]+size[x]-1,y);
 95         }
 96         if (k==4){
 97             read(x);
 98             printf("%d\n",query(1,dfn[x],dfn[x]+size[x]-1));
 99         }
100     }
101     return 0;
102 }

【模板】樹鏈剖分