等差数列
求1+2+3+...+n
http://www.nowcoder.com/questionTerminal/7a0da8fc483247ff8800059e12d7caf1
class Solution {
public:
int Sum_Solution(int n) {
double a = n;
a = ((1.0 + a) / 2) * a;
return (int)a;
}
};求1+2+3+...+n
http://www.nowcoder.com/questionTerminal/7a0da8fc483247ff8800059e12d7caf1
class Solution {
public:
int Sum_Solution(int n) {
double a = n;
a = ((1.0 + a) / 2) * a;
return (int)a;
}
};相关推荐