2024-07-12
한어Русский языкEnglishFrançaisIndonesianSanskrit日本語DeutschPortuguêsΕλληνικάespañolItalianoSuomalainenLatina
Utriusque cellae valor supra et ad sinistram determinatur, ideo supremae et sinistrae cellae primo initialized oportet. Quia quaestio postulat, ut solum deorsum et dextrorsum movearis, 1 cellae supremae et sinistrae initialized ad 1 .
temporis complexionem; O (m n) O (m*n)O****(m∗n)
Spatium complexionis: O (m n) O (m*n)O****(m∗n)
// c++
class Solution {
public:
int uniquePaths(int m, int n) {
vector<vector<int>> dp(m, vector(n,0));
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];
}
};
Similis est idea praecedenti quaestioni, et adduntur impedimenta ex praecedenti quaestione. In dp ordinata numerus semitarum ad cellulam (i, j) significat, et obstaculum positio 0 in dp ordinata est. Incipiens ab initializatione primi ordinis et columnae, si impedimentum in viis apparet, cellae post impedimentum non attingi possunt, et valores ordinatae dp respondentes omnes 0 erunt.
temporis complexionem; O (m n) O (m*n)O****(m∗n)
Spatium complexionis: O (m n) O (m*n)O****(m∗n)
// c++
class Solution {
public:
int uniquePathsWithObstacles(vector<vector<int>>& obstacleGrid) {
vector<vector<int>> dp(obstacleGrid.size(), vector(obstacleGrid[0].size(), 0));
// 标志单元格是否可到达
bool flag = true;
// 初始化第一行
for(int i=0; i<obstacleGrid.size(); i++){
if(obstacleGrid[i][0] == 1) {
// 可以直接break
flag = false;
}
if(flag) dp[i][0] = 1;
else dp[i][0] = 0;
}
// 标志单元格是否可到达
flag = true;
// 初始化第一列
for(int j=0; j<obstacleGrid[0].size(); j++){
if(obstacleGrid[0][j] == 1) {
// 可以直接break
flag = false;
}
if(flag) dp[0][j] = 1;
else dp[0][j] = 0;
}
// 计算dp数组
for(int i=1; i<obstacleGrid.size(); i++){
for(int j=1; j<obstacleGrid[0].size(); j++){
if(obstacleGrid[i][j]==1) continue;
dp[i][j] = dp[i-1][j] + dp[i][j-1];
}
}
return dp[obstacleGrid.size()-1][obstacleGrid[0].size()-1];
}
};