关于数据结构的题，请问大家知道答案么？

Question

1 设n为正整数, 分析下列各程序段中加下划线的语句的程序步数。
(1) for(int i = 1; i <= n; i++) (2) x= 0; y = 0;
for (int j = 1; j <= n; j++) { for (inti = 1; i <= n; i++)
c[i][j] = 0.0; for(int j = 1; j <= i; j++)
for (int k = 1; k <= n; k++) for (int k = 1; k <= j; k++)
c[i][j] = c[i][j] + a[i][k] *b[k][j]; x = x + y;
}
(3) inti = 1, j = 1; (4) int i=0;
while (i<=n&& j<=n) { do {
i = i + 1; j = j + i; for(int j = 1; j <= n; j++)
} i = 1 + j;
}while ( i < 100 + n );

Answer 1

(1):循环次数Sn=n^3
(2):循环次数Sn=X1+X2+..+Xn,Xn=1+2+..+n，即:Sn=n*(n+1)*(n+2)/6
(3):循环次数k满足k*(k+1)/2<=n，即：k<=(2n+0.25)^0.5-0.5
(4):死循环：内循环使得i=n+1，外循环条件i=n+1<100+n永远成立