题解 | #把字符串转换成整数#
把字符串转换成整数
https://www.nowcoder.com/practice/1277c681251b4372bdef344468e4f26e
class Solution { public: bool checkNum(char c) { if(c >= '0' && c <= '9') return true; if(c == '+' || c == '-') return true; return false; } int StrToInt(string str) { string s; int flag = 1; for(size_t i = 0; i < str.size(); i++) { if(!checkNum(str[i])) { return 0; } if(str[0] == '+') { flag = 1; } if(str[0] == '-') { flag = -1; } if(str[i] != '+' && str[i] != '-') s+=str[i]; } int num = 0; for(size_t i = 0; i < s.size(); i++) { num = num * 10 + (s[i] - '0'); } num *= flag; return num; } };