http://www.lydsy.com/JudgeOnline/problem.php?id=1452
题意:n×m的矩阵上每个点有个颜色,现在有q个操作:1 x y c 将点(x,y)的颜色改为c;2 x1 x2 y1 y2 c 询问矩阵x1y1-x2y2颜色为c的格子数目
#include <bits/stdc++.h> using namespace std; const int N=301; int n, m; int S[101][N][N], col[N][N]; void upd1(int c[N], int x, int w) { for(; x<=m; x+=x&-x) c[x]+=w; } void upd2(int c[N][N], int x, int y, int w) { for(; x<=n; x+=x&-x) upd1(c[x], y, w); } int sum1(int c[N], int x) { int ret=0; for(; x; x-=x&-x) ret+=c[x]; return ret; } int sum2(int c[N][N], int x, int y) { int ret=0; for(; x; x-=x&-x) ret+=sum1(c[x], y); return ret; } void upd(int c[N][N], int x, int y, int s) { upd2(c, x, y, s); } int sum(int c[N][N], int xa, int ya, int xb, int yb) { int ret=0; ret+=sum2(c, xb, yb); // cout << " ret: " << ret << endl; ret-=sum2(c, xb, ya-1); ret-=sum2(c, xa-1, yb); ret+=sum2(c, xa-1, ya-1); return ret; } int main() { scanf("%d %d", &n, &m); for(int i=1; i<=n; ++i) for(int j=1; j<=m; ++j) { int x; scanf("%d", &x); col[i][j]=x; upd(S[x], i, j, 1); } int q; scanf("%d", &q); for(int cc=0; cc<q; ++cc) { int ch; scanf("%d", &ch); if(ch==1) { int x, y, cl; scanf("%d %d %d", &x, &y, &cl); upd(S[col[x][y]], x, y, -1); col[x][y]=cl; upd(S[col[x][y]], x, y, 1); } else { int xa, xb, ya, yb, w; scanf("%d%d%d%d%d", &xa, &xb, &ya, &yb, &w); printf("%d\n", sum(S[w], xa, ya, xb, yb)); } } return 0; }
二维bit......