1073. Scientific Notation (20)

    字符串处理

#include <iostream>#include <cstdio>#include <cstdlib>using namespace std;int main(){string s;cin >> s;if(s.empty()) return 0;bool neg = false;if(s[0] == '-'){neg = true;s = s.substr(1);}else if(s[0] == '+'){s = s.substr(1);}auto pos = s.find('E');string left = s.substr(0, pos);string right = s.substr(pos+1);bool less = false;if(right[0] == '-'){less = true;right = right.substr(1);}else if(right[0] == '+'){right = right.substr(1);}int exp = atoi(right.c_str());if(less){auto pos = left.find('.');for(int i = pos; i <= exp; ++i){left = "0"+left;pos = pos+1;}for(int i = 0; i < exp; ++i){swap(left[pos], left[pos-1]);pos = pos-1;}}else{auto pos = left.find('.');int n = left.size() - (pos+1);for(int i = n; i < exp; ++i)left = left + "0";for(int i = 0; i < exp; ++i){swap(left[pos], left[pos+1]);pos = pos + 1;}if(left.find('.') == left.size()-1){left = left.substr(0, left.size()-1);}}if(neg) printf("-");printf("%s", left.c_str());return 0;}