动态规划算法2
LeetCode 62 不同路径 2023.12.2
int uniquePaths(int m, int n) {
vector<vector<int>> dp(m, vector<int>(n));
for (int i = 0; i < m; i++)
dp[i][0] = 1;
for (int j = 0; j < n; j++)
dp[0][j] = 1;
for (int i = 1; i < m; i++)
{
for (int j = 1; j < n; j++)
dp[i][j] = dp[i-1][j] + dp[i][j-1];
}
return dp[m-1][n-1];
}
LeetCode 63 不同路径-ii 2023.12.2
int uniquePathsWithObstacles(vector<vector<int>>& obstacleGrid) {
int row = obstacleGrid.size();
int col = obstacleGrid[0].size();
vector<vector<int>> dp(row, vector<int>(col));
int sym = 0;
for (int i = 0; i < row; i++)
{
if(sym == 0 && obstacleGrid[i][0] == 0)
dp[i][0] = 1;
else
{
dp[i][0] = 0;
sym = 1;
}
}
sym = 0;
for (int j = 0; j < col; j++)
{
if(sym == 0 && obstacleGrid[0][j] == 0)
dp[0][j] = 1;
else
{
dp[0][j] = 0;
sym = 1;
}
}
for (int i = 1; i < row; i++)
{
for(int j = 1; j < col; j++)
{
if(obstacleGrid[i][j] == 0)
dp[i][j] = dp[i-1][j] + dp[i][j-1];
else
dp[i][j] = 0;
}
}
return dp[row-1][col-1];
}