BZOJ2243 [SDOI2011]染色(树链剖分+线段树合并)
题目链接 BZOJ2243
树链剖分 ++ 线段树
线段树每个节点维护lclc, rcrc, ss
lclc代表该区间的最左端的颜色,rcrc代表该区间的最右端的颜色
ss代表该区间的所有连续颜色段数(仅考虑该区间)
lazylazy表示延迟信息。
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 | #include <bits/stdc++.h> using namespace std; #define rep(i, a, b) for (int i(a); i <= (b); ++i) #define dec(i, a, b) for (int i(a); i >= (b); --i) #define lson i << 1, L, mid #define rson i << 1 | 1, mid + 1, R typedef long long LL; const int N = 1e5 + 10; const int A = 21; vector < int > v[N]; int n, m; int c[N]; int f[N][A]; int lazy[N << 2], s[N << 2], lc[N << 2], rc[N << 2]; int h[N], deep[N], sz[N]; int son[N]; int tot = 0; int top[N]; int LCA( int a, int b){ if (deep[a] < deep[b]) swap(a, b); for ( int i = 0, delta = deep[a] - deep[b]; delta; delta >>= 1, ++i) if (delta & 1) a = f[a][i]; if (a == b) return a; dec(i, 19, 0) if (f[a][i] != f[b][i]) a = f[a][i], b = f[b][i]; return f[a][0]; } inline void pushup( int i){ lc[i] = lc[i << 1]; rc[i] = rc[i << 1 | 1]; if (rc[i << 1] ^ lc[i << 1 | 1]) s[i] = s[i << 1] + s[i << 1 | 1]; else s[i] = s[i << 1] + s[i << 1 | 1] - 1; } inline void pushdown( int i, int L, int R){ int tmp = lazy[i]; if (tmp == -1 || L == R) return ; s[i << 1] = s[i << 1 | 1] = 1; lazy[i << 1] = lazy[i << 1 | 1] = tmp; lc[i << 1] = rc[i << 1] = tmp; lc[i << 1 | 1] = rc[i << 1 | 1] = tmp; lazy[i] = -1; } void dfs1( int x, int fa, int dep){ sz[x] = 1; deep[x] = dep; if (fa){ f[x][0] = fa; for ( int i = 0; f[f[x][i]][i]; ++i) f[x][i + 1] = f[f[x][i]][i]; } int ct = ( int )v[x].size(); rep(i, 0, ct - 1){ int u = v[x][i]; if (u == fa) continue ; dfs1(u, x, dep + 1); sz[x] += sz[u]; if (sz[son[x]] < sz[u]) son[x] = u; } } void dfs2( int x, int tp){ h[x] = ++tot; top[x] = tp; if (son[x]) dfs2(son[x], tp); int ct = ( int )v[x].size(); rep(i, 0, ct - 1){ int u = v[x][i]; if (u == f[x][0] || u == son[x]) continue ; dfs2(u, u); } } void build( int i, int L, int R){ s[i] = 1; lazy[i] = -1; if (L == R) return ; int mid = (L + R) >> 1; build(lson); build(rson); } void change( int i, int L, int R, int l, int r, int val){ pushdown(i, L, R); if (L == l && R == r){ lc[i] = rc[i] = val; s[i] = 1; lazy[i] = val; return ; } int mid = (L + R) >> 1; if (r <= mid) change(lson, l, r, val); else if (l > mid) change(rson, l, r, val); else { change(lson, l, mid, val); change(rson, mid + 1, r, val); } pushup(i); } int query( int i, int L, int R, int l, int r){ pushdown(i, L, R); if (L == l && R == r) return s[i]; int mid = (L + R) >> 1; if (r <= mid) return query(lson, l, r); else if (l > mid) return query(rson, l, r); else { int tmp = 1; if (rc[i << 1] ^ lc[i << 1 | 1]) tmp = 0; return query(lson, l, mid) + query(rson, mid + 1, r) - tmp; } } int getcolor( int i, int L, int R, int x){ pushdown(i, L, R); if (L == R) return lc[i]; int mid = (L + R) >> 1; if (x <= mid) return getcolor(lson, x); else return getcolor(rson, x); } int solvesum( int x, int tp){ int ret = 0; for (; top[x] ^ top[tp] ;){ ret += query(1, 1, n, h[top[x]], h[x]); if (getcolor(1, 1, n, h[top[x]]) == getcolor(1, 1, n, h[f[top[x]][0]])) --ret; x = f[top[x]][0]; } ret += query(1, 1, n, h[tp], h[x]); return ret; } void solvechange( int x, int tp, int val){ for (; top[x] ^ top[tp]; ){ change(1, 1, n, h[top[x]], h[x], val); x = f[top[x]][0]; } change(1, 1, n, h[tp], h[x], val); } void solve(){ int x, y, z; dfs1(1, 0, 0); dfs2(1, 1); build(1, 1, n); rep(i, 1, n) change(1, 1, n, h[i], h[i], c[i]); rep(i, 1, m){ char ch[10]; scanf ( "%s" , ch); if (ch[0] == 'Q' ){ scanf ( "%d%d" , &x, &y); int t = LCA(x, y); printf ( "%d\n" , solvesum(x, t) + solvesum(y, t) - 1); } else { scanf ( "%d%d%d" , &x, &y, &z); int t = LCA(x, y); solvechange(x, t, z); solvechange(y, t, z); } } } void init(){ scanf ( "%d%d" , &n, &m); rep(i, 1, n) scanf ( "%d" , c + i); rep(i, 2, n){ int x, y; scanf ( "%d%d" , &x, &y); v[x].push_back(y); v[y].push_back(x); } } int main(){ init(); solve(); return 0; } |
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