1453: [蓝桥杯2019初赛]数列求值

#include <iostream>
using namespace std;

int solve(int n) {
    if (n <= 3) {
        return 1;
    }
    int a = 1, b = 1, c = 1, res;
    for (int i = 4; i <= n; i++) {
         // 这里要记得取余
        res = (a + b + c) % 10000;
        //往后移动一位 
        a = b;
        b = c;
        c = res;
    }
    return res;
}

int main() {
    int n = solve(20190324);
    cout<<n<<endl;
    return 0;
}