BZOJ1858 [Scoi2010]序列操作(线段树)

题目链接 [Scoi2010]序列操作

考验代码能力的一道好题。

思想还是很简单的(直接上线段树),但是比较难写。

#include <bits/stdc++.h>

using namespace std;

#define REP(i,n)                for(int i(0); i <  (n); ++i)
#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 for_edge(i,x) for(int i = H[x]; i; i = X[i]) #define LL long long
#define ULL unsigned long long
#define MP make_pair
#define PB push_back
#define FI first
#define SE second
#define INF 1 << 30 const int N = 200000 + 10;
const int M = 10000 + 10;
const int Q = 1000 + 10;
const int A = 30 + 1; struct segTree{
int len;
int maxn[2], lmax[2], rmax[2], sum[2];
} segtree[N << 2]; int a[N], de_cover[N << 2], de_turn[N << 2];
int n, m, op, x, y; segTree update(segTree x, segTree y){
segTree ans;
ans.len = x.len + y.len;
rep(i, 0, 1){
ans.sum[i] = x.sum[i] + y.sum[i];
ans.lmax[i] = (x.lmax[i] == x.len ? x.len + y.lmax[i] : x.lmax[i]);
ans.rmax[i] = (y.rmax[i] == y.len ? x.rmax[i] + y.len : y.rmax[i]);
ans.maxn[i] = max(max(x.maxn[i], y.maxn[i]), max(ans.lmax[i], ans.rmax[i]));
ans.maxn[i] = max(ans.maxn[i], x.rmax[i] + y.lmax[i]);
} return ans;
} void build(int i, int l, int r){
if (l == r){
int z = a[l];
segtree[i].len = segtree[i].sum[z] = segtree[i].lmax[z] = segtree[i].rmax[z] = segtree[i].maxn[z] = 1;
segtree[i].sum[z ^ 1] = segtree[i].lmax[z ^ 1] = segtree[i].rmax[z ^ 1] = segtree[i].maxn[z ^ 1] = 0;
de_cover[i] = -1, de_turn[i] = 0;
return ;
} int mid = (l + r) >> 1;
build(i << 1, l, mid);
build(i << 1 | 1, mid + 1, r);
segtree[i] = update(segtree[i << 1], segtree[i << 1 | 1]);
de_cover[i] = -1, de_turn[i] = 0;
} void paint_cover(int i, int z){
de_cover[i] = z;
de_turn[i] = 0;
segtree[i].sum[z] = segtree[i].lmax[z] = segtree[i].rmax[z] = segtree[i].maxn[z] = segtree[i].len;
segtree[i].sum[z ^ 1] = segtree[i].lmax[z ^ 1] = segtree[i].rmax[z ^ 1] = segtree[i].maxn[z ^ 1] = 0;
} void paint_turn(int i, int z){
if (z != -1){
de_cover[i] ^= 1;
segtree[i].sum[z] = segtree[i].lmax[z] = segtree[i].rmax[z] = segtree[i].maxn[z] = 0;
segtree[i].sum[z ^ 1] = segtree[i].lmax[z ^ 1] = segtree[i].rmax[z ^ 1] = segtree[i].maxn[z ^ 1] = segtree[i].len;
}
else{
de_turn[i] ^= 1;
swap(segtree[i].sum[0], segtree[i].sum[1]);
swap(segtree[i].lmax[0], segtree[i].lmax[1]);
swap(segtree[i].rmax[0], segtree[i].rmax[1]);
swap(segtree[i].maxn[0], segtree[i].maxn[1]);
}
} void pushdown(int i){
if (de_cover[i] != -1){
paint_cover(i << 1, de_cover[i]);
paint_cover(i << 1 | 1, de_cover[i]);
de_cover[i] = -1;
}
if (de_turn[i]){
paint_turn(i << 1, de_cover[i << 1]);
paint_turn(i << 1 | 1, de_cover[i << 1 | 1]);
de_turn[i] = 0;
}
} void insert_cover(int i, int l, int r, int x, int y, int z){
if (x <= l && y >= r){
paint_cover(i, z);
return ;
} pushdown(i);
int mid = (l + r) >> 1;
if (x <= mid) insert_cover(i << 1, l, mid, x, y, z);
if (y > mid) insert_cover(i << 1 | 1, mid + 1, r, x, y, z);
segtree[i] = update(segtree[i << 1], segtree[i << 1 | 1]);
} void insert_turn(int i, int l, int r, int x, int y){
if (x <= l && y >= r){
paint_turn(i, de_cover[i]);
return ;
} pushdown(i);
int mid = (l + r) >> 1;
if (x <= mid) insert_turn(i << 1, l, mid, x, y);
if (y > mid) insert_turn(i << 1 | 1, mid + 1, r, x, y);
segtree[i] = update(segtree[i << 1], segtree[i << 1 | 1]);
} int query_sum(int i, int l, int r, int x, int y){
int sum = 0;
if (x <= l && y >= r){ return segtree[i].sum[1];}
int mid = (l + r) >> 1;
pushdown(i);
if (x <= mid) sum += query_sum(i << 1, l, mid, x, y);
if (y > mid) sum += query_sum(i << 1 | 1, mid + 1, r, x, y);
return sum;
} segTree query_con(int i, int l ,int r, int x, int y){
segTree ans1, ans2;
bool f1 = false, f2 = false;
if (x <= l && y >= r) return segtree[i];
pushdown(i); int mid = (l + r) >> 1;
if (x <= mid) ans1 = query_con(i << 1, l, mid, x, y), f1 = true;
if (y > mid) ans2 = query_con(i << 1 | 1, mid + 1, r, x, y), f2 = true;
if (f1 && f2) return update(ans1, ans2);
else return f1 ? ans1 : ans2;
} int main(){ scanf("%d%d", &n, &m);
rep(i, 1, n) scanf("%d", a + i);
build(1, 1, n);
while (m--){
scanf("%d%d%d", &op, &x, &y);
++x, ++y;
if (op == 0) insert_cover(1, 1, n, x, y, 0);
if (op == 1) insert_cover(1, 1, n, x, y, 1);
if (op == 2) insert_turn(1, 1, n, x, y);
if (op == 3) printf("%d\n", query_sum(1, 1, n, x, y));
if (op == 4) printf("%d\n", query_con(1, 1, n, x, y).maxn[1]);
} return 0; }
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