9095 1,2,3 더하기

#include <stdio.h>
 
int main() {    
    int t;
    scanf("%d", &t);
    
    while (t--) {
        int n;
        scanf("%d", &n);
 
        if (n == 1) {
            printf("1\n");
            continue;
        }
        else if (n == 2) {
            printf("2\n");
            continue;
        }
        else if (n == 3) {
            printf("4\n");
            continue;
        }
 
        long long a = 1, b = 2, c = 4, rst;
        for (int i = 4; i <= n; i++) {
            rst = a + b + c;
            a = b;
            b = c;
            c = rst;
        }
 
        printf("%lld\n", rst);
 
    }
}