下列程序输出杨辉三角形，横线处应填入：
#define N 35
int a[N][N];
int main() {
int n; cin >> n;
for (int i = 1; i <= n; i++)
for (int j = 1; j <= i; j++) {
if (j == 1 || j == i)
a[i][j] = 1;
else
__________ // 在此处填入选项
}
// 输出 a[i][j] ...
return 0;
}
- A. a[i][j] = a[i-1][j-1] + a[i-1][j];
- B. a[i][j] = a[i][j-1] + a[i-1][j];
- C. a[i][j] = a[i-1][j] + a[i-1][j];
- D. a[i][j] = a[i-1][j-1] + a[i][j];
正确答案：A