diff --git a/solution/0000-0099/0008.String to Integer (atoi)/README.md b/solution/0000-0099/0008.String to Integer (atoi)/README.md index a1c189c4a6ce7..87634a3e1f38a 100644 --- a/solution/0000-0099/0008.String to Integer (atoi)/README.md +++ b/solution/0000-0099/0008.String to Integer (atoi)/README.md @@ -214,6 +214,36 @@ class Solution { } ``` +#### C++ + +```cpp +class Solution { +public: + int myAtoi(string s) { + int i = 0, n = s.size(); + while (i < n && s[i] == ' ') + ++i; + + int sign = 1; + if (i < n && (s[i] == '-' || s[i] == '+')) { + sign = s[i] == '-' ? -1 : 1; + ++i; + } + + int res = 0; + while (i < n && isdigit(s[i])) { + int digit = s[i] - '0'; + if (res > INT_MAX / 10 || (res == INT_MAX / 10 && digit > INT_MAX % 10)) { + return sign == 1 ? INT_MAX : INT_MIN; + } + res = res * 10 + digit; + ++i; + } + return res * sign; + } +}; +``` + #### Go ```go diff --git a/solution/0000-0099/0008.String to Integer (atoi)/README_EN.md b/solution/0000-0099/0008.String to Integer (atoi)/README_EN.md index 7603001843b45..05ee6458e6711 100644 --- a/solution/0000-0099/0008.String to Integer (atoi)/README_EN.md +++ b/solution/0000-0099/0008.String to Integer (atoi)/README_EN.md @@ -160,7 +160,6 @@ class Solution: i = 0 while s[i] == ' ': i += 1 - # 仅包含空格 if i == n: return 0 sign = -1 if s[i] == '-' else 1 @@ -168,11 +167,9 @@ class Solution: i += 1 res, flag = 0, (2**31 - 1) // 10 while i < n: - # 非数字,跳出循环体 if not s[i].isdigit(): break c = int(s[i]) - # 溢出判断 if res > flag or (res == flag and c > 7): return 2**31 - 1 if sign > 0 else -(2**31) res = res * 10 + c @@ -190,7 +187,6 @@ class Solution { if (n == 0) return 0; int i = 0; while (s.charAt(i) == ' ') { - // 仅包含空格 if (++i == n) return 0; } int sign = 1; @@ -198,9 +194,7 @@ class Solution { if (s.charAt(i) == '-' || s.charAt(i) == '+') ++i; int res = 0, flag = Integer.MAX_VALUE / 10; for (; i < n; ++i) { - // 非数字,跳出循环体 if (s.charAt(i) < '0' || s.charAt(i) > '9') break; - // 溢出判断 if (res > flag || (res == flag && s.charAt(i) > '7')) return sign > 0 ? Integer.MAX_VALUE : Integer.MIN_VALUE; res = res * 10 + (s.charAt(i) - '0'); @@ -210,6 +204,36 @@ class Solution { } ``` +#### C++ + +```cpp +class Solution { +public: + int myAtoi(string s) { + int i = 0, n = s.size(); + while (i < n && s[i] == ' ') + ++i; + + int sign = 1; + if (i < n && (s[i] == '-' || s[i] == '+')) { + sign = s[i] == '-' ? -1 : 1; + ++i; + } + + int res = 0; + while (i < n && isdigit(s[i])) { + int digit = s[i] - '0'; + if (res > INT_MAX / 10 || (res == INT_MAX / 10 && digit > INT_MAX % 10)) { + return sign == 1 ? INT_MAX : INT_MIN; + } + res = res * 10 + digit; + ++i; + } + return res * sign; + } +}; +``` + #### Go ```go @@ -282,8 +306,6 @@ const myAtoi = function (str) { #### C# ```cs -// https://leetcode.com/problems/string-to-integer-atoi/ - public partial class Solution { public int MyAtoi(string str) diff --git a/solution/0000-0099/0008.String to Integer (atoi)/Solution.cpp b/solution/0000-0099/0008.String to Integer (atoi)/Solution.cpp new file mode 100644 index 0000000000000..72fc381920bf2 --- /dev/null +++ b/solution/0000-0099/0008.String to Integer (atoi)/Solution.cpp @@ -0,0 +1,25 @@ +class Solution { +public: + int myAtoi(string s) { + int i = 0, n = s.size(); + while (i < n && s[i] == ' ') + ++i; + + int sign = 1; + if (i < n && (s[i] == '-' || s[i] == '+')) { + sign = s[i] == '-' ? -1 : 1; + ++i; + } + + int res = 0; + while (i < n && isdigit(s[i])) { + int digit = s[i] - '0'; + if (res > INT_MAX / 10 || (res == INT_MAX / 10 && digit > INT_MAX % 10)) { + return sign == 1 ? INT_MAX : INT_MIN; + } + res = res * 10 + digit; + ++i; + } + return res * sign; + } +};