字符串转化为整形（面试题 49）

#include "iostream"using namespace std;bool gInvaliddata =false;bool gNegative =false;int index;int Sum=0;int strToInt(char* string){if (string ==NULL){gInvaliddata =true;return 0;}if (string[0] =='-'){gNegative =true;index =1;while(string[index]!=0){if (string[index]<'0'||string[index]>'9'){gInvaliddata =true;break;}Sum*=10;Sum +=string[index++] -'0';}}else{index =0;Sum =0;while (string[index] !=0){if (string[index]<'0'||string[index]>'9'){gInvaliddata =true;break;}Sum*=10;Sum +=string[index++] -'0';}}if (gNegative){Sum =Sum*(-1);}return Sum;}void main(){char array[10] ={"-534"}; int data =strToInt(array);if (gInvaliddata){cout<<"传入字符非法!\n";}else{cout<<data+13<<endl;}}