题目链接：http://poj.org/problem?id=2155
题意：给一个01矩阵，两个操作，翻转：子矩阵里每一个数都由0变1，1变0。 查询：查询某一点是0还是1。
一直以为二维线段树就是开一个线段树数组的我…
这题暴力更新每一个小矩形，翻转就+1，最后看看某点的奇偶。
写屎了，特别注意的是在外层查询的时候要先把当前层的内层query掉，接着再向下扩展。这样外层就不用lazy啦
1 #include <algorithm>
2 #include <iostream>
3 #include <iomanip>
4 #include <cstring>
5 #include <climits>
6 #include <complex>
7 #include <cassert>
8 #include <cstdio>
9 #include <bitset>
10 #include <vector>
11 #include <deque>
12 #include <queue>
13 #include <stack>
14 #include <ctime>
15 #include <set>
16 #include <map>
17 #include <cmath>
18 using namespace std;
19
20 #define lrt rt << 1
21 #define rrt rt << 1 | 1
22 const int maxn = 1010;
23
24 typedef struct NodeY {
25 int val, sign;
26 }NodeY;
27
28 typedef struct NodeX {
29 NodeY segY[maxn<<2];
30
31 void build(int l, int r, int rt) {
32 segY[rt].val = segY[rt].sign = 0;
33 if(l == r) return;
34 int mid = (l + r) >> 1;
35 build(l, mid, lrt);
36 build(mid+1, r, rrt);
37 }
38
39 void pushdown(int l, int r, int rt) {
40 if(segY[rt].sign) {
41 int mid = (l + r) >> 1;
42 segY[lrt].sign += segY[rt].sign;
43 segY[rrt].sign += segY[rt].sign;
44 segY[lrt].val += (mid - l + 1) * segY[rt].sign;
45 segY[rrt].val += (r - mid) * segY[rt].sign;
46 segY[rt].sign = 0;
47 }
48 }
49
50 void update(int L, int R, int l, int r, int rt) {
51 if(L <= l && r <= R) {
52 segY[rt].sign++;
53 segY[rt].val += (r - l + 1);
54 return;
55 }
56 pushdown(l, r, rt);
57 int mid = (l + r) >> 1;
58 if(L <= mid) update(L, R, l, mid, lrt);
59 if(mid < R) update(L, R, mid+1, r, rrt);
60 }
61
62 int query(int pos, int l, int r, int rt) {
63 if(l == r) return segY[rt].val;
64 pushdown(l, r, rt);
65 int mid = (l + r) >> 1;
66 int ret = 0;
67 if(pos <= mid) ret += query(pos, l, mid, lrt);
68 else ret += query(pos, mid+1, r, rrt);
69 return ret;
70 }
71 }NodeX;
72
73 int n, q;
74 NodeX segX[maxn<<2];
75
76 void build(int l, int r, int rt) {
77 segX[rt].build(1, n, 1);
78 if(l == r) return;
79 int mid = (l + r) >> 1;
80 build(l, mid, lrt);
81 build(mid+1, r, rrt);
82 }
83
84 void update(int yl, int yr, int L, int R, int l, int r, int rt) {
85 if(L <= l && r <= R) {
86 segX[rt].update(yl, yr, 1, n, 1);
87 return;
88 }
89 int mid = (l + r) >> 1;
90 if(L <= mid) update(yl, yr, L, R, l, mid, lrt);
91 if(mid < R) update(yl, yr, L, R, mid+1, r, rrt);
92 }
93
94 int query(int x, int y, int l, int r, int rt) {
95 int ret = segX[rt].query(y, 1, n, 1);
96 if(l == r) return ret;
97 int mid = (l + r) >> 1;
98 if(x <= mid) ret += query(x, y, l, mid, lrt);
99 else ret += query(x, y, mid+1, r, rrt);
100 return ret;
101 }
102
103 char op[3];
104 int xa, ya, xb, yb;
105
106 int main() {
107 // freopen("in", "r", stdin);
108 int T;
109 scanf("%d", &T);
110 while(T--) {
111 scanf("%d%d",&n,&q);
112 build(1, n, 1);
113 while(q--) {
114 scanf("%s", op);
115 if(op[0] == ‘C‘) {
116 scanf("%d%d%d%d",&xa,&ya,&xb,&yb);
117 update(ya, yb, xa, xb, 1, n, 1);
118 }
119 else {
120 scanf("%d%d",&xa,&ya);
121 printf("%d\n", query(xa, ya, 1, n, 1) % 2);
122 }
123 }
124 printf("\n");
125 }
126 return 0;
127 }
按位翻转也可以，不过要加个pushdown：
1 #include <algorithm>
2 #include <iostream>
3 #include <iomanip>
4 #include <cstring>
5 #include <climits>
6 #include <complex>
7 #include <cassert>
8 #include <cstdio>
9 #include <bitset>
10 #include <vector>
11 #include <deque>
12 #include <queue>
13 #include <stack>
14 #include <ctime>
15 #include <set>
16 #include <map>
17 #include <cmath>
18 using namespace std;
19
20 #define lrt rt << 1
21 #define rrt rt << 1 | 1
22 const int maxn = 1010;
23
24 typedef struct NodeY {
25 bool sign;
26 }NodeY;
27
28 typedef struct NodeX {
29 NodeY segY[maxn<<2];
30 void build(int l, int r, int rt) {
31 segY[rt].sign = 0;
32 if(l == r) return;
33 int mid = (l + r) >> 1;
34 build(l, mid, lrt);
35 build(mid+1, r, rrt);
36 }
37 void pushdown(int rt) {
38 if(segY[rt].sign) {
39 segY[lrt].sign ^= 1; segY[rrt].sign ^= 1;
40 segY[rt].sign = 0;
41 }
42 }
43 void update(int L, int R, int l, int r, int rt) {
44 if(L <= l && r <= R) {
45 segY[rt].sign ^= 1;
46 return;
47 }
48 pushdown(rt);
49 int mid = (l + r) >> 1;
50 if(L <= mid) update(L, R, l, mid, lrt);
51 if(mid < R) update(L, R, mid+1, r, rrt);
52 }
53 int query(int pos, int l, int r, int rt) {
54 if(l == r) return segY[rt].sign;
55 pushdown(rt);
56 int mid = (l + r) >> 1;
57 if(pos <= mid) return query(pos, l, mid, lrt);
58 else return query(pos, mid+1, r, rrt);
59 }
60 }NodeX;
61
62 int n, q;
63 NodeX segX[maxn<<2];
64
65 void build(int l, int r, int rt) {
66 segX[rt].build(1, n, 1);
67 if(l == r) return;
68 int mid = (l + r) >> 1;
69 build(l, mid, lrt);
70 build(mid+1, r, rrt);
71 }
72
73 void update(int yl, int yr, int L, int R, int l, int r, int rt) {
74 if(L <= l && r <= R) {
75 segX[rt].update(yl, yr, 1, n, 1);
76 return;
77 }
78 int mid = (l + r) >> 1;
79 if(L <= mid) update(yl, yr, L, R, l, mid, lrt);
80 if(mid < R) update(yl, yr, L, R, mid+1, r, rrt);
81 }
82
83 int query(int x, int y, int l, int r, int rt) {
84 int ret = segX[rt].query(y, 1, n, 1);
85 if(l == r) return ret;
86 int mid = (l + r) >> 1;
87 if(x <= mid) ret ^= query(x, y, l, mid, lrt);
88 else ret ^= query(x, y, mid+1, r, rrt);
89 return ret;
90 }
91
92 char op[3];
93 int xa, ya, xb, yb;
94
95 int main() {
96 // freopen("in", "r", stdin);
97 int T;
98 scanf("%d", &T);
99 while(T--) {
100 scanf("%d%d",&n,&q);
101 build(1, n, 1);
102 while(q--) {
103 scanf("%s", op);
104 if(op[0] == ‘C‘) {
105 scanf("%d%d%d%d",&xa,&ya,&xb,&yb);
106 update(ya, yb, xa, xb, 1, n, 1);
107 }
108 else {
109 scanf("%d%d",&xa,&ya);
110 printf("%d\n", query(xa, ya, 1, n, 1));
111 }
112 }
113 printf("\n");
114 }
115 return 0;
116 }
时间： 2024-12-26 14:14:49