解题思路:
注意事项:
参考代码:
#include<bits/stdc++.h>
using namespace std;
float seqSum(short n); //有规律数列求和
int main() {
short N = 0;
cin >> N;
cout << fixed << setprecision(2) << seqSum(N) << endl;
return 0;
}
float seqSum(short n) {
float res = 0; //求和
short numerator = 2; //分子,初始为2
short denominator = 1; //分母,初始为1
for (short i = 0; i < n; i++) {
res += (float)numerator / denominator; //注意和(float)(numerator / denominator)的区别
short tempDen = denominator; //分母的副本
denominator = numerator; //数列下一个数的分母是上一个数的分子
numerator += tempDen; //数列下一个数的分子是上一个数的分子和分母之和
}
return res;
}
0.0分
0 人评分