java--杨辉三角

package test111111;

public class Test11 { 

	public static void main(String[] args){
		printYanghui();

	}

	//先总结一般规律，再讨论特殊情况，再做图形调整
	public static void printYanghui() {
		int rowMax = 6;
		int[][] arr = new int[rowMax][rowMax];
		for(int row=0;row<rowMax;row++) {
			for(int k=0;k<rowMax-row;k++) {
				System.out.print(" ");
			}

			for(int col=0;col<=row;col++) {
				if(col==row||col==0||row==0) {  //特殊情况
					arr[row][col] = 1;
				}else {
					arr[row][col] = arr[row-1][col-1]+arr[row-1][col];	//一般规律
				}
				System.out.print(arr[row][col]+" ");
			}
			System.out.println("");
		}

		for(int row=0;row<rowMax;row++) {
			for(int col=0;col<rowMax;col++) {
				System.out.print(arr[row][col]+" ");
			}
			System.out.println("");
		}
	}
}

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