输入输出示例

请输入层数: 10 0 12 345 6789 01234 567890 1234567 89012345 678901234 5678901234

待分析代码

int line_number, now_number;
int i,row;
cout << "请输入行数: ";
cin >> line_number;
now_number = 0;
for (row = 1; row < line_number + 1; row++) { // L1
for (i = 0; i < row; i++) { // L2
cout << now_number;
now_number += 1;
if (now_number == 10) now_number = 0; // L3
}
cout << endl;
}