118:杨辉三角
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src/main/java/leetcode/editor/cn/PascalsTriangle.java
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src/main/java/leetcode/editor/cn/PascalsTriangle.java
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//给定一个非负整数 numRows,生成杨辉三角的前 numRows 行。
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//
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//
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//
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// 在杨辉三角中,每个数是它左上方和右上方的数的和。
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//
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// 示例:
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//
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// 输入: 5
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//输出:
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//[
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// [1],
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// [1,1],
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// [1,2,1],
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// [1,3,3,1],
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// [1,4,6,4,1]
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//]
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// Related Topics 数组 动态规划
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// 👍 525 👎 0
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package leetcode.editor.cn;
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import java.util.ArrayList;
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import java.util.List;
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//118:杨辉三角
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public class PascalsTriangle{
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public static void main(String[] args) {
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//测试代码
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Solution solution = new PascalsTriangle().new Solution();
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}
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//力扣代码
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//leetcode submit region begin(Prohibit modification and deletion)
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class Solution {
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public List<List<Integer>> generate(int numRows) {
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List<List<Integer>> result = new ArrayList<>();
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for (int i = 0; i < numRows; i++) {
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List<Integer> list = new ArrayList<>();
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if(i==0){
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list.add(1);
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result.add(list);
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continue;
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}
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List<Integer> bef = result.get(i-1);
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for (int j = 0; j <= i; j++) {
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if(j==0||j==i){
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list.add(1);
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}else{
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list.add(bef.get(j-1)+ bef.get(j));
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}
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}
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result.add(list);
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}
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return result;
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}
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}
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//leetcode submit region end(Prohibit modification and deletion)
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}
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src/main/java/leetcode/editor/cn/PascalsTriangle.md
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src/main/java/leetcode/editor/cn/PascalsTriangle.md
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<p>给定一个非负整数 <em>numRows,</em>生成杨辉三角的前 <em>numRows </em>行。</p>
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<p><img alt="" src="https://upload.wikimedia.org/wikipedia/commons/0/0d/PascalTriangleAnimated2.gif"></p>
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<p><small>在杨辉三角中,每个数是它左上方和右上方的数的和。</small></p>
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<p><strong>示例:</strong></p>
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<pre><strong>输入:</strong> 5
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<strong>输出:</strong>
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[
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[1],
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[1,1],
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[1,2,1],
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[1,3,3,1],
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[1,4,6,4,1]
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]</pre>
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<div><div>Related Topics</div><div><li>数组</li><li>动态规划</li></div></div>\n<div><li>👍 525</li><li>👎 0</li></div>
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