cf luogu 被自己菜到自闭了/kk 既然是子矩阵,那么惯用套路为枚举矩阵上下边界,然后\(O(n)\)扫描求解.这题里要从左往右枚举右端点,然后看左端点最多能放到哪,那就对于每个数求出在上下边界中,在他左边的最右边的数的位置,然后左端点必须大于这个位置(如果在同一列那就不能包含这一列),那么合法的左边界为所选区间内左边扩展位置的最大值.每次扩展下边界,然后让多出来的这一行数更新每一列往左最多的扩展位置,这里要用到set,所以要\(O(n^3logn)\) 考虑优化,如果从下到上枚举上边界,…

Largest Submatrix Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 2018    Accepted Submission(s): 967 Problem Description Now here is a matrix with letter 'a','b','c','w','x','y','z' and you ca…

Largest Submatrix of All 1’s Time Limit: 5000MS   Memory Limit: 131072K Total Submissions: 8551   Accepted: 3089 Case Time Limit: 2000MS Description Given a m-by-n (0,1)-matrix, of all its submatrices of all 1’s which is the largest? By largest we me…

Problem Description Now here is a matrix with letter 'a','b','c','w','x','y','z' and you can change 'w' to 'a' or 'b', change 'x' to 'b' or 'c', change 'y' to 'a' or 'c', and change 'z' to 'a', 'b' or 'c'. After you changed it, what's the largest sub…

Given a m-by-n (0,1)-matrix, of all its submatrices of all 1’s which is the largest? By largest we mean that the submatrix has the most elements. Input The input contains multiple test cases. Each test case begins with m and n (1 ≤ m, n ≤ 2000) on li…

codeforces 407D Largest Submatrix 3 题意 找出最大子矩阵,须满足矩阵内的元素互不相等. 题解 官方做法 http://codeforces.com/blog/entry/11333 \(O(n^6)\) 枚举子矩阵,暴力check. \(O(n^4)\) 枚举上下边界,双指针. \(O(n^3log_2n)\) 假设当前上边界 \(up\), 下边界 \(down\),\(R_i\) 表示当 \(i\) 为左边界时,右边界最大是 \(R_i\). 当 \(do…

Given a m-by-n (0,1)-matrix, of all its submatrices of all 1's which is the largest? By largest we mean that the submatrix has the most elements. Input The input contains multiple test cases. Each test case begins with m and n (1 ≤ m, n ≤ 2000) on li…

POJ 3494 Largest Submatrix of All 1’s Description Given a m-by-n (0,1)-matrix, of all its submatrices of all 1’s which is the largest? By largest we mean that the submatrix has the most elements. Input The input contains multiple test cases. Each tes…

Largest Submatrix of All 1’s Given a m-by-n (0,1)-matrix, of all its submatrices of all 1’s which is the largest? By largest we mean that the submatrix has the most elements. Input The input contains multiple test cases. Each test case begins with m …

http://acm.hdu.edu.cn/showproblem.php? pid=2870 Largest Submatrix Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 1569    Accepted Submission(s): 748 Problem Description Now here is a matrix wi…