摘要: 我们知道一维前缀和是可以这么求的: for (int i = 1; i <= n; ++i) a[i] += a[i - 1]; 而二维前缀和是可以这么求的: for (int i = 1; i <= n; ++i) for (int j = 1; j <= n; ++j) a[i][j] = a[ 阅读全文
posted @ 2019-03-08 17:20 withoutpower 阅读(750) 评论(1) 推荐(1) 编辑