UVa Problem Solution: 848 - Fmt

At the first look, this problem seems to be tricky to solve. However, if you implement all the specifications precisely, it would be already solved. There's no need to "translate" the problem's specifications.

Code:
/*************************************************************************
* Copyright (C) 2008 by liukaipeng *
* liukaipeng at gmail dot com *
*************************************************************************/

/* @JUDGE_ID 00000 848 C++ "Fmt" */

#include <iostream>
#include <fstream>
#include <string>
#include <vector>

using namespace std;

int const linesize = 72;
int const buffsize = 2*1024*1024;

int fmt(char *src, int isize, char *dest)
{
int osize = 0;
for (int first = 0, last = first; first < isize; first = last) {
for (int next = last, nonblank = 0, word = 0; last < isize; last = next) {
// search for the next word
for (; next < isize && src[next] != ' ' && src[next] != '/n'; ++next) {
++nonblank;
}
++word;
// keep line break
if (next < isize && src[next] == '/n' &&
(src[next+1] == ' ' || src[next+1] == '/n' ||
nonblank == 0 || next + 1 == isize)) {
last = next + 1;
break;
}
// break the line
if (next - first > linesize) {
// exhaust all blanks
for (last = word > 1 ? last : next + 1; src[last] == ' '; ++last) {}
src[last-1] = '/n';
break;
}
src[next++] = ' '; // eliminate newline
}
copy(src + first, src + last, dest + osize);
osize += last - first;
if (dest[osize-1] == '/n') { // eliminate trailing spaces
for (; osize > 1 && dest[osize-2] == ' '; --osize) {}
dest[osize-1] = '/n';
}
}

return osize;
}

int main(int argc, char *argv[])
{
#ifndef ONLINE_JUDGE
filebuf in, out;
cin.rdbuf(in.open((string(argv[0]) + ".in").c_str(), ios_base::in));
cout.rdbuf(out.open((string(argv[0]) + ".out").c_str(), ios_base::out));
#endif

char src[buffsize];
char dest[buffsize];
cin.read(src, buffsize);
int isize = cin.gcount();
int osize = fmt(src, isize, dest);
cout.write(dest, osize);

return 0;
}