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leetcode_java/src/main/java/LeetCodeJava/Array/SpiralMatrix.java
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,132 @@ | ||
| package LeetCodeJava.Array; | ||
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| // https://leetcode.com/problems/spiral-matrix/description/ | ||
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| import java.util.ArrayList; | ||
| import java.util.List; | ||
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| public class SpiralMatrix { | ||
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| // V0 | ||
| // IDEA : array + index op | ||
| // https://github.com/yennanliu/CS_basics/blob/master/leetcode_python/Array/spiral-matrix.py | ||
| // TODO : implement below | ||
| // public List<Integer> spiralOrder(int[][] matrix) { | ||
| // | ||
| // } | ||
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| // V0' | ||
| // IDEA : array + index op | ||
| public List<Integer> spiralOrder_(int[][] matrix) { | ||
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| int row = matrix.length; | ||
| int col = matrix[0].length; | ||
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| List<Integer> ans = new ArrayList<>(); | ||
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| if(row < 1){ | ||
| return ans; | ||
| } | ||
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| int startR = 0; | ||
| int startCol = 0; | ||
| int i = 0; | ||
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| while(startR <row && startCol<col){ | ||
| for(i= startCol; i< col; ++i){ | ||
| ans.add(matrix[startR][i]); | ||
| } | ||
| startR++; | ||
| for(i = startR; i<row; ++i){ | ||
| ans.add(matrix[i][col-1]); | ||
| } | ||
| col--; | ||
| if(startR < row){ | ||
| for(i = col-1; i>= startCol;--i){ | ||
| ans.add(matrix[row-1][i]); | ||
| } | ||
| row--; | ||
| } | ||
| if(startCol < col){ | ||
| for(i = row-1; i>= startR;--i){ | ||
| ans.add(matrix[i][startCol]); | ||
| } | ||
| startCol++; | ||
| } | ||
| } | ||
| return ans; | ||
| } | ||
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| // V1 | ||
| // https://leetcode.com/problems/spiral-matrix/solutions/4700215/easy-solution/ | ||
| public List<Integer> spiralOrder_1(int[][] m) { | ||
| int l=0,r=m[0].length-1,u=0,d=m.length-1; | ||
| List<Integer> ll=new ArrayList<>(); | ||
| while(true){ | ||
| if(l<=r){ | ||
| for(int i=l;i<=r;++i){ | ||
| ll.add(m[u][i]); | ||
| } | ||
| u++; | ||
| }else break; | ||
| if(u<=d){ | ||
| for(int i=u;i<=d;++i){ | ||
| ll.add(m[i][r]); | ||
| } | ||
| r--; | ||
| }else break; | ||
| if(l<=r){ | ||
| for(int i=r;i>=l;--i){ | ||
| ll.add(m[d][i]); | ||
| } | ||
| d--; | ||
| }else break; | ||
| if(u<=d){ | ||
| for(int i=d;i>=u;--i){ | ||
| ll.add(m[i][l]); | ||
| } | ||
| l++; | ||
| }else break; | ||
| } | ||
| return ll; | ||
| } | ||
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| // V2 | ||
| // https://leetcode.com/problems/spiral-matrix/solutions/3503095/java-runtime-0-ms-beats-100-memory-40-8-mb-beats-46-17/ | ||
| public List<Integer> spiralOrder_2(int[][] matrix) { | ||
| int row = matrix.length; | ||
| List<Integer> ans = new ArrayList<>(); | ||
| if(row<1){ | ||
| return ans; | ||
| } | ||
| int col = matrix[0].length; | ||
| int startR = 0; | ||
| int startCol = 0; | ||
| int i =0; | ||
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| while(startR<row&& startCol<col){ | ||
| for(i= startCol; i< col; ++i){ | ||
| ans.add(matrix[startR][i]); | ||
| } | ||
| startR++; | ||
| for(i = startR; i<row;++i){ | ||
| ans.add(matrix[i][col-1]); | ||
| } | ||
| col--; | ||
| if(startR<row){ | ||
| for(i = col-1; i>=startCol;--i){ | ||
| ans.add(matrix[row-1][i]); | ||
| } | ||
| row--; | ||
| } | ||
| if(startCol<col){ | ||
| for(i = row-1; i>=startR;--i){ | ||
| ans.add(matrix[i][startCol]); | ||
| } | ||
| startCol++; | ||
| } | ||
| } | ||
| return ans; | ||
| } | ||
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| } |