78 lines
1.6 KiB
Java
78 lines
1.6 KiB
Java
package com.leetcode.array;
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/**
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*
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* 旋转矩阵
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给你一幅由 N × N 矩阵表示的图像，其中每个像素的大小为 4 字节。请你设计一种算法，将图像旋转 90 度。
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不占用额外内存空间能否做到？
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示例 1:
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给定 matrix =
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[
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[1,2,3],
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[4,5,6],
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[7,8,9]
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],
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原地旋转输入矩阵，使其变为:
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[
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[7,4,1],
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[8,5,2],
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[9,6,3]
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]
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示例 2:
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给定 matrix =
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[
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[ 5, 1, 9,11],
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[ 2, 4, 8,10],
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[13, 3, 6, 7],
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[15,14,12,16]
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],
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原地旋转输入矩阵，使其变为:
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[
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[15,13, 2, 5],
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[14, 3, 4, 1],
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[12, 6, 8, 9],
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[16, 7,10,11]
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]
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作者：力扣 (LeetCode)
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链接：https://leetcode-cn.com/leetbook/read/array-and-string/clpgd/
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来源：力扣（LeetCode）
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著作权归作者所有。商业转载请联系作者获得授权，非商业转载请注明出处。
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答案解析：https://leetcode-cn.com/problems/rotate-matrix-lcci/solution/xuan-zhuan-ju-zhen-by-leetcode-solution/
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*/
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public class RotateMatrix {
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public void rotate(int[][] matrix) {
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int n = matrix.length;
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// 水平翻转
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for (int i = 0; i < n / 2; ++i) {
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for (int j = 0; j < n; ++j) {
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int temp = matrix[i][j];
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matrix[i][j] = matrix[n - i - 1][j];
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matrix[n - i - 1][j] = temp;
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}
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}
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// 主对角线翻转
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for (int i = 0; i < n; ++i) {
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for (int j = 0; j < i; ++j) {
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int temp = matrix[i][j];
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matrix[i][j] = matrix[j][i];
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matrix[j][i] = temp;
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}
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}
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}
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public static void main(String[] args) {
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}
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}
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