【BZOJ2333】【SCOI2011】棘手的操作

#include<bits/stdc++.h>
using namespace std;
#define MAXN	300005
#define INF	1e9
struct Node {
int lc, rc;
int maxnum, tag;
};
Node a[MAXN * 2];
int n, q, timer, size, dfn[MAXN], home[MAXN];
int f[MAXN], value[MAXN], rit[MAXN];
int x[MAXN], y[MAXN], z[MAXN];
char opt[MAXN][3];
vector <int> t[MAXN];
int F(int x) {
if (f[x] == x) return x;
else return f[x] = F(f[x]);
}
void dfs(int pos) {
dfn[pos] = ++timer;
for (unsigned i = 0; i < t[pos].size(); i++)
dfs(t[pos][i]);
}
void update(int x) {
a[x].maxnum = max(a[a[x].lc].maxnum, a[a[x].rc].maxnum);
}
void pushdown(int x) {
a[a[x].lc].tag += a[x].tag;
a[a[x].lc].maxnum += a[x].tag;
a[a[x].rc].tag += a[x].tag;
a[a[x].rc].maxnum += a[x].tag;
a[x].tag = 0;
}
void build(int pos, int l, int r) {
if (l == r) {
a[pos].maxnum = value[home[l]];
return;
}
int mid = (l + r) / 2;
a[pos].lc = ++size;
build(size, l, mid);
a[pos].rc = ++size;
build(size, mid + 1, r);
update(pos);
}
void maintain(int pos, int l, int r, int ql, int qr, int v) {
if (l == ql && r == qr) {
a[pos].tag += v;
a[pos].maxnum += v;
return;
}
int mid = (l + r) / 2;
pushdown(pos);
if (mid >= ql) maintain(a[pos].lc, l, mid, ql, min(mid, qr), v);
if (mid + 1 <= qr) maintain(a[pos].rc, mid + 1, r, max(mid + 1, ql), qr, v);
update(pos);
}
int query(int pos, int l, int r, int ql, int qr) {
if (l == ql && r == qr) return a[pos].maxnum;
int mid = (l + r) / 2, ans = -INF;
pushdown(pos);
if (mid >= ql) ans = max(ans, query(a[pos].lc, l, mid, ql, min(mid, qr)));
if (mid + 1 <= qr) ans = max(ans, query(a[pos].rc, mid + 1, r, max(mid + 1, ql), qr));
return ans;
}
int main() {
scanf("%d", &n);
for (int i = 1; i <= n; i++) {
scanf("%d", &value[i]);
f[i] = i; rit[i] = i;
}
scanf("%d", &q);
for (int i = 1; i <= q; i++) {
scanf("%s", opt[i]);
if (opt[i][0] == 'U') {
scanf("%d%d", &x[i], &y[i]);
int tx = F(x[i]), ty = F(y[i]);
if (tx == ty) continue;
f[ty] = tx; rit[tx] = rit[ty];
t[tx].push_back(ty);
}
if (opt[i][0] == 'A') {
if (opt[i][1] == '1') scanf("%d%d", &x[i], &y[i]);
if (opt[i][1] == '2') {
scanf("%d%d", &x[i], &y[i]);
x[i] = F(x[i]);
z[i] = rit[x[i]];
}
if (opt[i][1] == '3') scanf("%d", &y[i]);
}
if (opt[i][0] == 'F') {
if (opt[i][1] == '1') scanf("%d", &x[i]);
if (opt[i][1] == '2') {
scanf("%d", &x[i]);
x[i] = F(x[i]);
z[i] = rit[x[i]];
}
}
}
for (int i = 1; i <= n; i++)
if (f[i] == i) dfs(i);
for (int i = 1; i <= n; i++)
home[dfn[i]] = i;
build(0, 1, n);
for (int i = 1; i <= q; i++) {
if (opt[i][0] == 'A') {
if (opt[i][1] == '1') maintain(0, 1, n, dfn[x[i]], dfn[x[i]], y[i]);
if (opt[i][1] == '2') maintain(0, 1, n, dfn[x[i]], dfn[z[i]], y[i]);
if (opt[i][1] == '3') maintain(0, 1, n, 1, n, y[i]);
}
if (opt[i][0] == 'F') {
if (opt[i][1] == '1') printf("%d\n", query(0, 1, n, dfn[x[i]], dfn[x[i]]));
if (opt[i][1] == '2') printf("%d\n", query(0, 1, n, dfn[x[i]], dfn[z[i]]));
if (opt[i][1] == '3') printf("%d\n", query(0, 1, n, 1, n));
}
}
return 0;
}