P3833 [SHOI2012]魔法树
题目链接：https://www.luogu.org/problem/P3833
1 #include <stdio.h> 2 #include <algorithm> 3 #include <iostream> 4 #include <stdbool.h> 5 #include <stdlib.h> 6 #include <string> 7 #include <string.h> 8 #include <stack> 9 #include <queue> 10 #include <set> 11 #include <map> 12 #include <math.h> 13 14 #define INF 0x3f3f3f3f 15 #define LL long long 16 using namespace std; 17 18 const int maxn = 100050; 19 20 struct Edge{ 21 int to,next; 22 }edge[maxn*4]; 23 24 int head[maxn],tot; 25 26 void add_edge(int u,int v){ 27 edge[++tot] = Edge{v,head[u]}; 28 head[u] = tot; 29 //edge[tot] = Edge{u,head[v]}; 30 //head[v] = tot++; 31 } 32 33 int v[maxn]; 34 int fa[maxn]; 35 int siz[maxn]; 36 int dep[maxn]; 37 int son[maxn]; 38 39 void dfs1(int u,int f){ 40 fa[u] = f; 41 dep[u] = dep[f] + 1; 42 siz[u] = 1; 43 int maxsize = -1; 44 for (int i=head[u];~i;i=edge[i].next){ 45 int v = edge[i].to; 46 if (v == f){ 47 continue; 48 } 49 dfs1(v,u); 50 siz[u] += siz[v]; 51 if (siz[v] > maxsize){ 52 maxsize = siz[v]; 53 son[u] = v; 54 } 55 } 56 } 57 58 59 int tim; 60 int dfn[maxn]; 61 int top[maxn]; 62 int w[maxn]; 63 64 void dfs2(int u,int t){ 65 dfn[u] = ++tim; 66 top[u] = t; 67 w[tim] = v[u]; 68 if (!son[u]){ 69 return ; 70 } 71 dfs2(son[u],t); 72 for (int i=head[u];~i;i=edge[i].next){ 73 int v = edge[i].to; 74 if (v == fa[u] || v == son[u]){ 75 continue; 76 } 77 dfs2(v,v); 78 } 79 } 80 81 struct segment_tree{ 82 int l,r; 83 LL val; 84 int lazy; 85 }tree[maxn*4]; 86 87 void pushup(int nod){ 88 tree[nod].val = (tree[nod<<1].val + tree[(nod<<1)+1].val); 89 } 90 91 void pushdown(int nod){ 92 tree[nod<<1].lazy += tree[nod].lazy; 93 tree[(nod<<1)+1].lazy += tree[nod].lazy; 94 tree[nod<<1].val += (tree[nod<<1].r-tree[nod<<1].l + 1) * tree[nod].lazy; 95 tree[(nod<<1)+1].val += (tree[(nod<<1)+1].r-tree[(nod<<1)+1].l+1) * tree[nod].lazy; 96 tree[nod].lazy = 0; 97 } 98 99 void build (int l,int r,int nod){ 100 tree[nod].l = l; 101 tree[nod].r = r; 102 if (l == r){ 103 tree[nod].lazy = 0; 104 tree[nod].val = w[l]; 105 return ; 106 } 107 int mid = (l + r) >> 1; 108 build(l,mid,nod<<1); 109 build(mid+1,r,(nod<<1)+1); 110 pushup(nod); 111 } 112 113 114 void modify(int x,int y,int z,int k=1){ 115 int l = tree[k].l, r = tree[k].r; 116 if (x <= l && y>=r){ 117 tree[k].lazy += z; 118 tree[k].val += (r-l+1) * z; 119 return ; 120 } 121 if (tree[k].lazy){ 122 pushdown(k); 123 } 124 int mid = (l + r) >> 1; 125 if (x <= mid){ 126 modify(x,y,z,k<<1); 127 } 128 if (y > mid){ 129 modify(x,y,z,(k<<1)+1); 130 } 131 pushup(k); 132 } 133 134 LL query(int x,int y,int k=1){ 135 int l = tree[k].l,r = tree[k].r; 136 if (x <= l && y >= r){ 137 return tree[k].val; 138 } 139 if (tree[k].lazy){ 140 pushdown(k); 141 } 142 int mid = (l + r) >> 1; 143 LL sum = 0; 144 if (x <= mid){ 145 sum += query(x,y,k<<1); 146 } 147 if (y > mid){ 148 sum += query(x,y,(k<<1)+1); 149 } 150 return sum; 151 } 152 153 LL q_query(int x){ 154 return query(dfn[x],dfn[x]+siz[x]-1); 155 } 156 157 void mchain(int x,int y,int z) { 158 while (top[x] != top[y]) { 159 if (dep[top[x]] < dep[top[y]]) 160 swap(x, y); 161 modify(dfn[top[x]], dfn[x], z); 162 x = fa[top[x]]; 163 } 164 if (dep[x] > dep[y]) 165 swap(x, y); 166 modify(dfn[x], dfn[y], z); 167 } 168 169 170 int main(){ 171 int n; 172 scanf("%d",&n); 173 memset(head,-1, sizeof(head)); 174 for (int i=1;i<=n-1;i++){ 175 int x,y; 176 scanf("%d%d",&x,&y); 177 add_edge(x,y); 178 add_edge(y,x); 179 } 180 dfs1(0,0); 181 dfs2(0,0); 182 build(1,n,1); 183 int T; 184 scanf("%d",&T); 185 while (T--){ 186 char s[4]; 187 int x,y,z; 188 scanf("%s",s); 189 if (s[0] == 'A'){ 190 scanf("%d%d%d",&x,&y,&z); 191 mchain(x,y,z); 192 } 193 if (s[0] == 'Q') { 194 scanf("%d",&x); 195 printf("%lld\n",q_query(x)); 196 } 197 } 198 return 0; 199 }
