【POJ】2155 Matrix
二维树状数组。
1 /* poj2155 */ 2 #include <iostream> 3 #include <string> 4 #include <map> 5 #include <queue> 6 #include <vector> 7 #include <algorithm> 8 #include <cstdio> 9 #include <cmath> 10 #include <cstring> 11 #include <climits> 12 #include <cctype> 13 using namespace std; 14 15 #define MAXN 1005 16 17 bool cnt[MAXN][MAXN]; 18 int n, m; 19 20 inline int lowest(int x) { 21 return x&-x; 22 } 23 24 int sum(int x1, int y1) { 25 int i, j, k; 26 int ret = 0; 27 28 for (i=x1; i; i-=lowest(i)) 29 for (j=y1; j; j-=lowest(j)) 30 ret += cnt[i][j]; 31 return ret&1; 32 } 33 34 void update(int x1, int y1) { 35 int i, j, k; 36 37 for (i=x1; i<=n; i+=lowest(i)) 38 for (j=y1; j<=n; j+=lowest(j)) 39 cnt[i][j] = !cnt[i][j]; 40 } 41 42 int main() { 43 int t; 44 int i, j, k; 45 int x1, y1, x2, y2; 46 char s[3]; 47 48 #ifndef ONLINE_JUDGE 49 freopen("data.in", "r", stdin); 50 freopen("data.out", "w", stdout); 51 #endif 52 53 scanf("%d", &t); 54 while (t--) { 55 scanf("%d %d", &n, &m); 56 memset(cnt, false, sizeof(cnt)); 57 while (m--) { 58 scanf("%s", s); 59 if (s[0] == 'Q') { 60 scanf("%d %d", &x1, &y1); 61 k = sum(x1, y1); 62 if (k) 63 puts("1"); 64 else 65 puts("0"); 66 } else { 67 scanf("%d %d %d %d", &x1, &y1, &x2, &y2); 68 update(x1, y1); 69 update(x1, y2+1); 70 update(x2+1, y1); 71 update(x2+1, y2+1); 72 } 73 } 74 if (t) 75 putchar('\n'); 76 } 77 78 return 0; 79 }
