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: int StrToInt(string str) { if (str.empty()) { return 0; } int symbol = 1;//标记正负号 if (str[0] == '-') { symbol = -1; str[0] = '0';//字符零占位 } if (str[0] == '+') { symbol = 1; str[0] = '0';//字符零占位 } long long num = 0; for (int i = 0; i < str.size(); i++) { if (str[i] < '0' || str[i] > '9') { return 0; break; } else { num = num * 10; num = num + (str[i] - '0'); } } num = symbol * num; if (num > INT_MAX || num < INT_MIN) return 0; return num; } };