Create StringToInteger_atoi.cpp

https://leetcode.com/problems/string-to-integer-atoi/

Author: itsgauravsingh

StringToInteger_atoi.cpp

@@ -0,0 +1,85 @@
+class Solution {
+public:
+    int myAtoi(string str) {
+        int answer=0;
+        int i=0;
+        string s(str);
+        int l = s.length();
+        bool sign = true;
+        while(i<l && s[i] == ' ')
+            i++;
+        cout<<"\nall the leading whitespaces trimmed";
+        if((s[i]<'0' || s[i]>'9') && s[i] != '-' && s[i] !='+')
+            return 0;
+        cout<<"\nstarting the processing";
+        if(s[i] == '-') {
+            sign = false;
+            i++;
+            cout<<"\nNumber is negative";
+        } else if (s[i] == '+') {
+            i++;
+        }
+        
+        while(i<l) {
+            cout<<"\nhere is the element s["<<i<<"] \t"<<s[i];
+            if(s[i]==' ') {
+                break;
+            }
+            if(s[i] >= '0' && s[i] <='9') {
+                int x = s[i]-'0';
+                //cout<<"\n x="<<x;
+                if(sign && static_cast<long int>(answer)*10 + x >= INT_MAX) {
+                    return INT_MAX;
+                } else if (!sign && static_cast<long int>(answer)*10 + x > INT_MAX) {
+                    return INT_MIN;
+                }
+                answer = answer*10 + x;
+                i++;
+            } else {
+                return (sign ? answer : -answer);
+            }
+            cout<<"\nanswer= "<<answer;
+        }
+        return (sign ? answer : -answer);
+        
+    }
+};
+
+string stringToString(string input) {
+    assert(input.length() >= 2);
+    string result;
+    for (int i = 1; i < input.length() -1; i++) {
+        char currentChar = input[i];
+        if (input[i] == '\\') {
+            char nextChar = input[i+1];
+            switch (nextChar) {
+                case '\"': result.push_back('\"'); break;
+                case '/' : result.push_back('/'); break;
+                case '\\': result.push_back('\\'); break;
+                case 'b' : result.push_back('\b'); break;
+                case 'f' : result.push_back('\f'); break;
+                case 'r' : result.push_back('\r'); break;
+                case 'n' : result.push_back('\n'); break;
+                case 't' : result.push_back('\t'); break;
+                default: break;
+            }
+            i++;
+        } else {
+          result.push_back(currentChar);
+        }
+    }
+    return result;
+}
+
+int main() {
+    string line;
+    while (getline(cin, line)) {
+        string str = stringToString(line);
+        
+        int ret = Solution().myAtoi(str);
+
+        string out = to_string(ret);
+        cout << out << endl;
+    }
+    return 0;
+}