题目描述
棋盘
C++ 代码 (差分)
#include <iostream>
using namespace std;
#define int long long
const int N = 2010;
int a[N][N], d[N][N];
void insert(int x1, int y1, int x2, int y2, int c)
{
d[x1][y1] += c;
d[x1][y2 + 1] -= c;
d[x2 + 1][y1] -= c;
d[x2 + 1][y2 + 1] += c;
return;
}
signed main()
{
int n, m;
scanf("%lld%lld",&n,&m);
// 差分
while(m--)
{
int x1, y1, x2, y2;
scanf("%lld%lld%lld%lld",&x1,&y1,&x2,&y2);
insert(x1,y1,x2,y2,1);
}
// 求前缀和
for(int i = 1; i <= n; ++ i)
for(int j = 1; j <= n; ++ j)
d[i][j] += (d[i-1][j] + d[i][j-1] - d[i-1][j-1]);
// 遍历输出
for(int i = 1; i <= n; ++ i)
{
for(int j = 1; j <= n; ++ j)
if(d[i][j] & 1) printf("1");
else printf("0");
printf("\n");
}
return 0;
}