why this program gives me a "Debug Assertion Failed" Error Message while running
#include "stdafx.h"#include "iostream"#include "fstream"#include "string"using namespace std;int conv_ch(char b){int f;f=b;b=b+0;switch(b){case 48:f=0;break;case 49:f=1;break;case 50:f=2;break;case 51:f=3;break;case 52:f=4;break;case 53:f=5;break;case 54:f=6;break;case 55:f=7;break;case 56:f=8;break;case 57:f=9;break;default:f=0;}return f;} class Student{public:string id;size_t id_len;string first_name;size_t first_len;string last_name;size_t last_len;string phone;size_t phone_len;string grade;size_t grade_len;void print();void clean();};void Student::clean(){id.erase (id.begin()+6, id.end());first_name.erase (first_name.begin()+15, first_name.end());last_name.erase (last_name.begin()+15, last_name.end());phone.erase (phone.begin()+10, phone.end());grade.erase (grade.begin()+2, grade.end());}void Student::print(){int i;for(i=0;i<6;i++){cout<<id[i]; }cout<<endl;for(i=0;i<15;i++){cout<<first_name[i]; }cout<<endl;for(i=0;i<15;i++){cout<<last_name[i]; }cout<<endl;for(i=0;i<10;i++){cout<<phone[i]; }cout<<endl;for(i=0;i<2;i++){cout<<grade[i]; }cout<<endl;}int main(){Student k[80];char data[1200];int length,i,recn=0;int rec_length;int counter = 0;fstream myfile;char x1,x2;char y1,y2;char zz;int ad=0;int ser,j;myfile.open ("example.txt",ios::in);int right;int left;int middle;string key;while(!myfile.eof()){myfile.get(data,1200);char * pch;pch = strtok (data, "#");printf ("%s\n", pch);j=0;for(i=0;i<6;i++){k[recn].id[i]=data[j];j++;}for(i=0;i<15;i++){k[recn].first_name[i]=data[j];j++;}for(i=0;i<15;i++){k[recn].last_name[i]=data[j];j++;}for(i=0;i<10;i++){k[recn].phone[i]=data[j];j++;}for(i=0;i<2;i++){k[recn].grade[i]=data[j];j++;}recn++;j=0;}//cout<<recn;string temp1;size_t temp2;int temp3;for(i=0;i<recn-1;i++){for(j=0;j<recn-1;j++){ if(k[i].id.compare(k[j].id)<0){temp1 = k[i].first_name;k[i].first_name = k[j].first_name;k[j].first_name = temp1;temp2 = k[i].first_len;k[i].first_len = k[j].first_len;k[j].first_len = temp2;temp1 = k[i].last_name;k[i].last_name = k[j].last_name;k[j].last_name = temp1;temp2 = k[i].last_len;k[i].last_len = k[j].last_len;k[j].last_len = temp2;temp1 = k[i].grade;k[i].grade = k[j].grade;k[j].grade = temp1;temp2 = k[i].grade_len;k[i].grade_len = k[j].grade_len;k[j].grade_len = temp2;temp1 = k[i].id;k[i].id = k[j].id;k[j].id = temp1;temp2 = k[i].id_len;k[i].id_len = k[j].id_len;k[j].id_len = temp2;temp1 = k[i].phone;k[i].phone = k[j].phone;k[j].phone = temp1;temp2 = k[i].phone_len;k[i].phone_len = k[j].phone_len;k[j].phone_len = temp2;}}}for(i=0;i<recn-1;i++){k[i].clean();}char z;string id_sear;cout<<"Enter 1 to display , 2 to search , 3 to exit:";cin>>z;while(1){switch(z){case '1':for(i=0;i<recn-1;i++){k[i].print();}break;case '2':cin>>key;right=0;left=recn-2;while(right<=left){middle=((right+left)/2);if(key.compare(k[middle].id)==0){cout<<"Founded"<<endl;k[middle].print();break;}else if(key.compare(k[middle].id)<0){left=middle-1;}else{right=middle+1;}}break;case '3':exit(0);break;}cout<<"Enter 1 to display , 2 to search , 3 to exit:";cin>>z;}return 0;}the program reads from a file example.txt
313121crewwe matt 0114323111A # 433444cristinaee john 0113344325A+# 324311matte richee 3040554032B # the idea is to read fixed size field structure with a text seprator record strucutre
Best Answer
The assertion failure is thrown by one of the standard C++ library functions that you're calling with invalid parameters. Run it in a debugger and you should see exactly what call.
One thing that looks suspect: In Student::clean you make calls like:
first_name.erase (first_name.begin()+15, first_name.end());If the length of first_name is less than 15, this is likely to cause an assertion failure or other errors.