Scanning and Filtering a Source Program

You are given a C source program with single and multiple line comments. As the first step toward compilation you need to remove the comments and white space (extra spaces, tabs and newline characters). Develop a program that takes as input file the given source program and produces a filtered file as stated above. The program must also display both the files.

Session 1 by Nafis Islam on Scribd

	/* A program fragment */
	float x1 = 3.125;
	/* Definition of function f1 */
	double f1(int x)
	{
	double z;
	z = 0.01+x*5.5;
	return z;
	}
	/* Beginning of 'main'*/
	int main(void)
	{
	int n1;
	double z;
	n1=25;
	z=f1(n1);
	}

view raw input.txt hosted with ❤ by GitHub

float x1 = 3.125; double f1(int x) { double z; z = 0.01+x*5.5; return z; } int main(void) { int n1; double z; n1=25; z=f1(n1); }

view raw output.txt hosted with ❤ by GitHub

	#include<bits/stdc++.h>
	using namespace std;
	int main(){
	freopen("input.txt","r",stdin);
	freopen("output.txt","w",stdout);
	string s;
	vector<string>sp;
	int flag = 0;
	cerr<<"input:\n";
	while(getline(cin,s)){
	sp.push_back(s);
	}
	for(int i=0;i<sp.size();i++) cerr<<sp[i]<<"\n";
	cerr<<"\noutput:\n";
	int flag3 = -1;
	for(int i=0;i<sp.size();i++){
	s = "";
	int sz = sp[i].size();
	flag3 = -1;
	for(int j=0;j<sz;j++) if(sp[i][j]=='\t') sp[i][j] = ' ';
	for(int j=0;j<sz;j++){
	if(j!=sz-1 && sp[i][j]!=' ' && sp[i][j+1]==' ') s = s + sp[i][j] + ' ';
	else if(sp[i][j]!=' ') s += sp[i][j];
	}
	for(int j=0;j<sz;j++){
	if(sp[i][j]=='"'){
	flag3 = j;
	break;
	}
	}
	if(flag3!=-1){
	string p = "";
	for(int j=0;s[j]!='"';j++) p += s[j];
	p += "\"";
	for(int j=flag3+1,r=0;sp[i][j]!='"';j++) p += sp[i][j];
	for(int j=0,r=0;j<s.size();j++){
	if(s[j]=='"') r++;
	if(r==2) p +=s[j];
	}
	swap(s,p);
	}
	swap(sp[i],s);
	}
	//for(int i=0;i<sp.size();i++) cerr<<sp[i]<<"\n";
	int flag1 = 0,flag2=0;
	for(int i=0;i<sp.size();i++){
	int sz = sp[i].size();
	if(sz==0) continue;
	for(int j=0;j<sz;j++){
	if(j!=sz-1 && sp[i][j]=='/' && sp[i][j+1]=='/'){
	flag1 = 1;
	for(int k=0;k<j;k++){
	cout<<sp[i][k];
	cerr<<sp[i][k];
	}
	break;
	}
	if(j!=sz-1 && sp[i][j]=='/' && sp[i][j+1]=='*'){
	flag2 = 1;
	for(int k=0;k<j;k++){
	cout<<sp[i][k];
	cerr<<sp[i][k];
	}
	}
	if(j!=sz-1 && sp[i][j]=='*' && sp[i][j+1]=='/'){
	flag2 = 0;
	flag1 = 1;
	break;
	}
	}
	if(flag1){
	flag1 = 0;
	continue;
	}
	if(flag2){
	continue;
	}
	cout<<sp[i]<<" ";
	cerr<<sp[i]<<" ";
	}
	return 0;
	}

view raw Scanning and Filtering a Source Program.cpp hosted with ❤ by GitHub