#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<math.h>
将数组a的内容和数组b的内容进行交换(数组一样大)
int main()
{
int arr1[] = { 1,3,5,7,9 };
int arr2[] = { 3,4,5,6,7 };
int tmp;
int i = 0;
for (i = 0;i < sizeof(arr1) / sizeof(arr1[0]);i++)
{
tmp = arr1[i];
arr1[i] = arr2[i];
arr2[i] = tmp;
}
for (i =0 ;i < sizeof(arr1) / sizeof(arr1[0]);i++)
{
printf("%d ", arr1[i]);
}
printf("\n");
for (i = 0;i < sizeof(arr1) / sizeof(arr1[0]);i++)
{
printf("%d ", arr2[i]);
}
system("pause");
return 0;
}
main() {
int i;
float sum = 0.0,temp = 0.0;
for (i = 1;i <= 100;i++)
{
temp = pow(-1, i + 1);
sum = sum + temp * 1 / i;
}
printf("sum is %f\n", sum);system("pause");return 0;
}
编写程序数一下1-100所有整数中出现多少次数字9
main() {
int i;
for (i = 1;i <= 100;i++) {
if (i % 10 == 9) {
printf("%d ", i);
}
}
system("pause");
return 0;
}