1 #include <iostream> 2 3 using namespace std; 4 int toInteger(char string[]); 5 int main(){ 6 char string[100]={0}; 7 cin>>string; 8 cout<<toInteger(string)<<endl; 9 return 0; 10 } 11 12 int toInteger(char string[]) 13 { 14 //Your code is here 15 int ret = 0; 16 bool flag = true; 17 unsigned int idx = 0; 18 19 char c = string[idx]; 20 if (c == '+') { 21 flag = true; 22 ++idx; 23 } else if (c == '-') { 24 flag = false; 25 ++idx; 26 } 27 28 for (; (c=*(string + idx)) != '\0' && c >= '0' && c <= '9'; ++idx) { 29 if (flag) { 30 int temp = ret * 10 + c - '0'; 31 if (ret >= temp) { 32 return 2147483647; 33 } 34 else {ret = ret * 10 + c - '0';} 35 } 36 else { 37 int temp = ret * 10 + c - '0'; 38 if (ret >= temp) { 39 return -2147483648; 40 } 41 else {ret = ret * 10 + c - '0';} 42 } 43 44 } 45 return flag ? ret : -ret; 46 }