# Spiral Matrix II2024-01-06 09:57

Problem Description

``````public int[][] generateMatrix(int n) {
int maxNum = n * n;
int curNum = 1;
int[][] matrix = new int[n][n];
int row = 0;
int column = 0;
//left to right:row not change ,column++ , {0,1}
//up to bottom:row++,column not change, {1,0}
//right to left:row not change,column==,{0,-1}
//bottom to up:row--,column not change,{-1,0}
int[][] directions = {{0, 1}, {1, 0}, {0, -1}, {-1, 0}};
int directionIndex = 0;
while (curNum <= maxNum) {
matrix[row][column] = curNum;
curNum++;
int nextRow = row + directions[directionIndex][0];
int nextColumn = column + directions[directionIndex][1];
if (isChangeDirection(n, nextRow, nextColumn, matrix)) {
directionIndex = (directionIndex + 1) % 4; // 顺时针旋转至下一个方向
}
row = row + directions[directionIndex][0];
column = column + directions[directionIndex][1];
}
return matrix;
}

private static boolean isChangeDirection(int n, int nextRow, int nextColumn, int[][] matrix) {
return nextRow < 0 || nextRow >= n || nextColumn < 0 || nextColumn >= n || matrix[nextRow][nextColumn] != 0;
}

``````
Runtime Memory
0 ms 41.96 MB

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