力扣1006.笨阶乘

力扣1006.笨阶乘

• */直接算 ±放进栈

  • 最后再算±

•   class Solution {public:int clumsy(int n) {vector<int> st;st.push_back(n);n -- ;int idx=0;while(n > 0){if(idx % 4 == 0)st.back() *= n;else if(idx % 4 == 1)st.back() /= n;else if(idx % 4 == 2)st.push_back(n);elsest.push_back(-n);idx ++;n --;}int sum = 0;while(!st.empty()){sum += st.back();st.pop_back();}return sum;}};