题解 | 数楼梯
数楼梯
https://www.nowcoder.com/practice/c7e5f164fa5d471f8f83c90fe4ee3f05
#include <stdio.h>
int main(void) {
int n;
scanf("%d", &n);
if(n == 1){
printf("1\n");
return 0;
}
if(n == 2){
printf("2\n");
return 0;
}
long long a[100005];
a[0] = 1, a[1] = 2;
for(int i = 2; i <= n; i++){
a[i] = a[i-1] + a[i-2];
a[i] %= 998244353;
}
printf("%lld", a[n-1]);
return 0;
}
