题解 | 牛牛学数列5

#include <stdio.h>

int main() {
    int n;
    scanf("%d",&n);
    int a=1,b=1,c=1;
    if(n==1||n==2) {printf("1");return 0;}
    for(int i=3; i<=n; i++) {c=a+b;a=b;b=c;}
    printf("%d",b);
    return 0;
}