C语言学习练习220417

//计算n的阶乘：
#include
int main()
{
while (1)
{
int n = 0;
scanf("%d", &n);
if (n != 0)
{
int i = 0;
int ret = 1;
for (i = 1; i <= n; i++)
{
ret *= i;
}
printf("%d！=%d\n", n, ret);
ret = 1;
}
else
{
printf(“计算结束”);
break;
}
}
}
//计算n!+(n-1)!+…1;
int main()
{
int n = 0;
scanf("%d",&n);
int i = 0;
int sum = 0;
int ret = 1;
for (i=1;i<=n;i++)
{
ret *= i;
sum += ret;
}
printf("%d\n", sum);
}
//建立函数，实现有序数组找数：
int Find_n(int arr[],int n,int z)
{
int i = 0;
for (i = 0; i < z; i++)
{
if (arr[i] == n)
{
return i;
break;
}
}
if (i == z)
{
return -1;
}

}
int main()
{
int arr_1[] = {1,2,3,4,5,6,7,8,9,10,11};
int sz = sizeof(arr_1) / sizeof(arr_1[0]);
while (1)
{
int n = 0;
printf(“请输入要查找的数字：\n”);
scanf("%d",&n);
if (Find_n(arr_1, n,sz) != -1)
{
printf(“找到了，下标是：%d\n”, Find_n(arr_1,n,sz));
}
else
{
printf(“找不到！！！”);
break;
}
}
}