C++ 筆試基礎題 27 摺紙練習題 牛客網 7.11

請把紙條豎著放在桌?上，然後從紙條的下邊向上?對摺，壓出摺痕後再展 開。此時有1條摺痕，突起的?向指向紙條的背?，這條摺痕叫做「下」摺痕 ；突起的?向指向紙條正?的摺痕叫做「上」摺痕。如果每次都從下邊向上? 對摺，對摺N次。請從上到下計算出所有摺痕的?向。

給定折的次數n,請返回從上到下的摺痕的數組，若為下摺痕則對應元素為"down",若為上摺痕則為"up".

1

返回：["down"]

代碼寫的比較簡單：鏈接：https://www.nowcoder.com/courses/1/7/11來源：牛客網classFoldPaper {public: //遞歸調用voidfold(inti,intN,bool down,vector<string> &ret){if(i > N) return;fold(i + 1,N,true,ret);ret.push_back(down ? "down": "up");fold(i + 1,N,false,ret);} vector<string> foldPaper(intn) {vector<string> ret;fold(1,n,true,ret);returnret;}};鏈接：https://www.nowcoder.com/courses/1/7/11來源：牛客網classFoldPaper{public:voidfunc(inti,intn,stringret,vector<string>&v){if(i>n){return;}func(i+1,n,"down",v);ret=="down"?v.push_back("down"):v.push_back("up");func(i+1,n,"up",v);}vector<string>foldPaper(intn){vector<string>v;func(1,n,"down",v);returnv;}};
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