,C语言练习题,热心的朋友请进

求助,C语言练习题,热心的朋友请进!
用C语言实现以下习题:

1.99-98+97-96.......1

2.实现字符串倒序显示,
    字符串为 "i   love   you "处理后为   "uoy   evol   i "

在线等,谢谢了!

[解决办法]
1.
int reverse = 1;
int sum = 0;
for (int i = 99; i > = 1; i--) {
sum += i * reverse;
reverse = -reverse;
}

2.
char str[] = "i love you ";
int length = strlen(str);
for (int i = length - 1; i > = 0; i--) {
cout < < str[i]; // printf( "%c ", str[i]);
}

[解决办法]
1

int main()
{
int flag=-1;
int sum=0;
for(int i=99;i> 0;i--)
{
flag*=-1;
sum+=i*flag;
}
printf( "%d\n ",sum);
}