标签：style class blog code http tar
Given a m x n grid filled with non-negative numbers, find a path from top left to bottom right which minimizes the sum of all numbers along its path.
Note: You can only move either down or right at any point in time.
解题分析：
每次只能向下或者向右走，其实就是说明了 搜索过程中的状态扩展情况
设 f[i,j]表示 从原点到 grid[i][j]的最小路径和，则有以下动态规划特征式：
f[i,j] = min { f[i-1][j], f[i][j-1] } + grid[i][j]
注意边界情况
class Solution { public: int minPathSum(vector<vector<int> > &grid) { int nRow = grid.size(); int nCol = 0; if (nRow == 0) { return 0; } else { nCol = grid.at(0).size(); } vector<vector<int>> path(nRow, vector<int>(nCol, 0)); for (int i = 0; i < nRow; ++i) { for (int j = 0; j < nCol; ++j) { if (i == 0 && j == 0) path.at(0).at(0) = grid.at(0).at(0); if (i == 0 && j != 0) path.at(i).at(j) = path.at(i).at(j-1) + grid.at(i).at(j); if (i != 0 && j == 0) path.at(i).at(j) = path.at(i-1).at(j) + grid.at(i).at(j); if (i != 0 && j != 0) path.at(i).at(j) = std::min(path.at(i-1).at(j), path.at(i).at(j-1)) + grid.at(i).at(j); } } return path.at(nRow-1).at(nCol-1); } };
Leetcode:Minimum Path Sum 矩形网格最小路径和,布布扣,bubuko.com
Leetcode:Minimum Path Sum 矩形网格最小路径和
标签：style class blog code http tar
原文地址：http://www.cnblogs.com/wwwjieo0/p/3800184.html
