int climbStairs(int n) {
int i = 1;
int cur = 1, prev = 1, temp;
while(i < n){
temp = cur;
cur += prev;
prev = temp;
i++;
}
return cur;
}
int climbStairs(int n) {
int i = 1;
int cur = 1, prev = 1, temp;
while(i < n){
temp = cur;
cur += prev;
prev = temp;
i++;
}
return cur;
}