[BZOJ 2157] 旅游
切完题来水一发……
拥有良心样例数据的树链剖分模版题……
窝已经要突破天际了哈哈哈写这货都能有 250+ 行哈哈哈已经开始脑补 NOI 2005 维修数列了哈哈哈哈哈哈……（←发抽 ing）
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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 | /************************************************************** Problem: 2157 User: cyand1317 Language: C++ Result: Accepted Time:632 ms Memory:3472 kb****************************************************************/ #include <cstdio>#include <utility>#include <vector>static const int MAXN = 20006;static const int INF = 0x7fffffff;inline int min(int a, int b) { return a < b ? a : b; }inline int max(int a, int b) { return a > b ? a : b; }inline void swap(int &a, int &b) { static int t; t = a; a = b; b = t; } struct __sgt_node { int l, r, lch, rch; int sum, min, max; bool lz_rev;} t[MAXN * 2]; void sgt_push(int idx){ if (t[idx].lz_rev) { t[idx].lz_rev = false; t[idx].sum = -t[idx].sum; int x = t[idx].min; t[idx].min = -t[idx].max; t[idx].max = -x; if (t[idx].lch != -1) { t[t[idx].lch].lz_rev ^= 1; t[t[idx].rch].lz_rev ^= 1; } }}void sgt_update(int idx){ if (t[idx].lch != -1) { sgt_push(t[idx].lch); sgt_push(t[idx].rch); t[idx].sum = t[t[idx].lch].sum + t[t[idx].rch].sum; t[idx].min = min(t[t[idx].lch].min, t[t[idx].rch].min); t[idx].max = max(t[t[idx].lch].max, t[t[idx].rch].max); }}int sgt_querysum(int l, int r, int idx = 0){ sgt_push(idx); if (t[idx].l >= l && t[idx].r <= r) return t[idx].sum; int ret = 0; if (t[t[idx].lch].r >= l) ret += sgt_querysum(l, r, t[idx].lch); if (t[t[idx].rch].l <= r) ret += sgt_querysum(l, r, t[idx].rch); return ret;}int sgt_querymax(int l, int r, int idx = 0){ sgt_push(idx); if (t[idx].l >= l && t[idx].r <= r) return t[idx].max; int ret = -INF; if (t[t[idx].lch].r >= l) ret = max(ret, sgt_querymax(l, r, t[idx].lch)); if (t[t[idx].rch].l <= r) ret = max(ret, sgt_querymax(l, r, t[idx].rch)); return ret;}int sgt_querymin(int l, int r, int idx = 0){ sgt_push(idx); if (t[idx].l >= l && t[idx].r <= r) return t[idx].min; int ret = INF; if (t[t[idx].lch].r >= l) ret = min(ret, sgt_querymin(l, r, t[idx].lch)); if (t[t[idx].rch].l <= r) ret = min(ret, sgt_querymin(l, r, t[idx].rch)); return ret;}void sgt_pointset(int pos, int val, int idx = 0){ sgt_push(idx); if (t[idx].l == pos && t[idx].r == pos) { t[idx].sum = t[idx].min = t[idx].max = val; } else { if (pos <= t[t[idx].lch].r) sgt_pointset(pos, val, t[idx].lch); else sgt_pointset(pos, val, t[idx].rch); sgt_update(idx); }}void sgt_intvrev(int l, int r, int idx = 0){ sgt_push(idx); if (t[idx].l >= l && t[idx].r <= r) { t[idx].lz_rev ^= 1; } else { if (t[t[idx].lch].r >= l) sgt_intvrev(l, r, t[idx].lch); if (t[t[idx].rch].l <= r) sgt_intvrev(l, r, t[idx].rch); } sgt_update(idx);} int sgt_seq[MAXN];int sgt_build(int l, int r){ static int epoch = -1; int idx = ++epoch; t[idx].l = l; t[idx].r = r; t[idx].lz_rev = false; if (l == r) { t[idx].lch = t[idx].rch = -1; t[idx].sum = t[idx].min = t[idx].max = sgt_seq[l]; } else { int m = (l + r) >> 1; t[idx].lch = sgt_build(l, m); t[idx].rch = sgt_build(m + 1, r); sgt_update(idx); } return idx;} typedef std::pair<int, int> edge;#define dest first#define len secondtypedef std::vector<edge> edgelist; int n;edgelist e[MAXN];std::pair<int, int> e_list[MAXN]; int par[MAXN], dep[MAXN], sts[MAXN], pfc[MAXN];int tvn[MAXN], hct[MAXN];int par_dist[MAXN]; void hld_dfs1(int r = 0, int p = -1, int d = 0){ par[r] = p; dep[r] = d; sts[r] = 1; pfc[r] = -1; int max_sts = -1; for (edgelist::iterator i = e[r].begin(); i != e[r].end(); ++i) if (i->dest != p) { par_dist[i->dest] = i->len; hld_dfs1(i->dest, r, d + 1); sts[r] += sts[i->dest]; if (max_sts < sts[i->dest]) { max_sts = sts[i->dest]; pfc[r] = i->dest; } }}void hld_dfs2(int r = 0, int t = 0){ static int epoch = -1; tvn[r] = ++epoch; sgt_seq[epoch] = par_dist[r]; hct[r] = t; if (pfc[r] != -1) hld_dfs2(pfc[r], t); for (edgelist::iterator i = e[r].begin(); i != e[r].end(); ++i) if (i->dest != par[r] && i->dest != pfc[r]) hld_dfs2(i->dest, i->dest);}inline void hld_jumpsum(int &u, int &ans){ int v = hct[u]; ans += sgt_querysum(tvn[v], tvn[u]); u = par[v];}int hld_querysum(int u, int v){ if (dep[u] > dep[v]) swap(u, v); int ans = 0; while (hct[u] != hct[v]) { if (dep[hct[u]] < dep[hct[v]]) hld_jumpsum(v, ans); else hld_jumpsum(u, ans); } if (dep[u] > dep[v]) swap(u, v); if (u != v) ans += sgt_querysum(tvn[u] + 1, tvn[v]); return ans;}inline void hld_jumpmin(int &u, int &ans){ int v = hct[u]; ans = min(ans, sgt_querymin(tvn[v], tvn[u])); u = par[v];}int hld_querymin(int u, int v){ if (dep[u] > dep[v]) swap(u, v); int ans = INF; while (hct[u] != hct[v]) { if (dep[hct[u]] < dep[hct[v]]) hld_jumpmin(v, ans); else hld_jumpmin(u, ans); } if (dep[u] > dep[v]) swap(u, v); if (u != v) ans = min(ans, sgt_querymin(tvn[u] + 1, tvn[v])); return ans;}inline void hld_jumpmax(int &u, int &ans){ int v = hct[u]; ans = max(ans, sgt_querymax(tvn[v], tvn[u])); u = par[v];}int hld_querymax(int u, int v){ if (dep[u] > dep[v]) swap(u, v); int ans = -INF; while (hct[u] != hct[v]) { if (dep[hct[u]] < dep[hct[v]]) hld_jumpmax(v, ans); else hld_jumpmax(u, ans); } if (dep[u] > dep[v]) swap(u, v); if (u != v) ans = max(ans, sgt_querymax(tvn[u] + 1, tvn[v])); return ans;}inline void hld_jumprev(int &u){ int v = hct[u]; sgt_intvrev(tvn[v], tvn[u]); u = par[v];}void hld_pathrev(int u, int v){ if (dep[u] > dep[v]) swap(u, v); while (hct[u] != hct[v]) { if (dep[hct[u]] < dep[hct[v]]) hld_jumprev(v); else hld_jumprev(u); } if (dep[u] > dep[v]) swap(u, v); if (u != v) sgt_intvrev(tvn[u] + 1, tvn[v]);}inline void hld_pointset(int u, int v, int val){ if (par[u] == v) sgt_pointset(tvn[u], val); else sgt_pointset(tvn[v], val);} int main(){ scanf("%d", &n); int u, v, w; for (int i = 1; i < n; ++i) { scanf("%d%d%d", &u, &v, &w); e[u].push_back(edge(v, w)); e[v].push_back(edge(u, w)); e_list[i] = std::make_pair(u, v); } hld_dfs1(); hld_dfs2(); sgt_build(0, n - 1); int m; scanf("%d", &m); char op[16]; int a1, a2; do { scanf("%s%d%d", op, &a1, &a2); if (/*!strcmp(op, "C")*/ op[0] == 'C') hld_pointset(e_list[a1].first, e_list[a1].second, a2); else if (/*!strcmp(op, "N")*/ op[0] == 'N') hld_pathrev(a1, a2); else if (/*!strcmp(op, "SUM")*/ op[0] == 'S') printf("%d\n", hld_querysum(a1, a2)); else if (/*!strcmp(op, "MIN")*/ op[1] == 'I') printf("%d\n", hld_querymin(a1, a2)); else /*if (!strcmp(op, "MAX"))*/ printf("%d\n", hld_querymax(a1, a2)); } while (--m); return 0;} |
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