标签：
Given a 2D binary matrix filled with 0‘s and 1‘s, find the largest square containing all 1‘s and return its area.
For example, given the following matrix:
1 0 1 0 0 1 0 1 1 1 1 1 1 1 1 1 0 0 1 0Return 4.
Credits:
Special thanks to @Freezen for adding this problem and creating all test cases.
Dynamic Programming
dp[x][y] = min(dp[x - 1][y - 1], dp[x][y - 1], dp[x - 1][y]) + 1
#include<iostream>
#include<vector>
#include<math.h>
using namespace std;
int maximalSquare(vector<vector<char>>& matrix)
{
if(matrix.empty())
return 0;
int m=matrix.size();
int n=matrix[0].size();
vector<vector<int>> ma;
vector<int> ve;
for(int i=0;i<n;i++)
ve.push_back(0);
for(int i=0;i<m;i++)
{
ma.push_back(ve);
}
int re=0;
for(int i=0;i<n;i++)
{
if(matrix[0][i]==‘1‘)
{
ma[0][i]=1;
re=1;
}
else
ma[0][i]=0;
}
for(int j=0;j<m;j++)
{
if(matrix[j][0]==‘1‘)
{
ma[j][0]=1;
re=1;
}
else
ma[j][0]=0;
}
if(m==1)
return re;
for(int i=1;i<m;i++)
{
for(int j=1;j<n;j++)
{
if(matrix[i][j]==‘1‘)
{
ma[i][j]=min(min(ma[i][j-1],ma[i-1][j]),ma[i-1][j-1])+1;
if(re<ma[i][j])
re=ma[i][j];
}
else
ma[i][j]=0;
}
}
return re*re;
}
int main()
{
vector<vector<char>> matrix;
vector<char> ma;
ma.push_back(‘0‘);
matrix.push_back(ma);
cout<<maximalSquare(matrix)<<endl;
}
leetcode_221题——Maximal Square （动态规划）
标签：
原文地址：http://www.cnblogs.com/yanliang12138/p/4634900.html
