求助：输入输出流【简单的文件读写】这段程序怎么改？
#include<fstream.h>
#include<process.h>
int lookfor(char a[5][10],int n,char key[])
{
int j=0,r=1;
for (int m=0;m<n;m++)
{
while(key[j]!='\0')
{
if (a[m][j]!=key[j])
{
r=-1;
}
}
if(r==1)
return m;
}
return r;
}
void main()
{
ifstream in("a.txt");
if (!in)
{
cout<<"error!"<<endl;
exit(0);
}
char a[100];
char keyword[5][10]={"include","class","do","for","if"};
int count[5]={0};
while (!in.eof())
{
in.getline(a,101);//处理每一行
for (int j=0;j<101 &&a[j]!='\0';j++)
{
int k=0;
char word[30]=" ";
while(!(a[j]>='a'&&a[j]<='z'))
j++;
while (a[j]>='a' &&a[j]<='z')
word[k++]=a[j++];
word[k]='\0';
int res=lookfor(keyword,5,word);
if (res!=-1)
{
count[res]++;
}
}
}
for (int i=0;i<5;i++)
{
cout<<keyword[i]<<":"<<count[i]<<endl;
}
in.close();
} 输入输出流 c++
[解决办法]
int lookfor(char a[5][10],int n,char key[])
{
int j=0,r=1;
for (int m=0;m<n;m++)
{
if(strcmp(key, a[m]) == 0)
return m;
}
return -1;
}
#include <algorithm>
#include <fstream>
#include <list>
#include <set>
#include <string>
namespace {
std::string kF1 = "1.txt";
std::string kF2 = "2.txt";
const char kDelimiter = ' ';
} // namespace
// Before loading data to container, there is a chance to modify a line by using
// paramter function_process_line who is a function pointer.
// Set it NULL, if you need not preprocess an input line.
template<typename ContainerType>
ContainerType LoadDataToContainer(const std::string& filename,
void(*function_process_line)(std::string&)) {
std::ifstream infile(filename, std::ios_base::in);
if (!infile) {
throw std::ios_base::failure("Failed to open file: " + filename);
}
ContainerType container;
std::string line;
while (infile) {
std::getline(infile, line);
if (line.empty()) {
break;
}
if (function_process_line) {
function_process_line(line);
}
// Note: parameter 1 is not meaningful to any container type.
container.insert(container.end(), line);
}
infile.close();
return container;
}
template<typename IteratorType>
void WriteDataToFile(
const std::string& filename, const IteratorType& b, const IteratorType& e) {
std::ofstream outfile(filename, std::ios_base::out);
if (!outfile) {
throw std::ios_base::failure("Failed to open file: " + filename);
}
for (IteratorType iter = b; iter != e; ++iter) {
outfile << *iter << std::endl;
}
outfile.close();
}
inline void RetainOnlyFirstColumn(std::string& line) {
// To keep things simple, it is assumed there must be kDelimiter in line.
line.erase(line.begin() + line.find(kDelimiter), line.begin() + line.size());
}
int main(int argc, char* argv[]) {
auto s = LoadDataToContainer<std::set<std::string>>(kF1, RetainOnlyFirstColumn);
auto l = LoadDataToContainer<std::list<std::string>>(kF2, NULL);
for (auto iter = l.begin(); iter != l.end();
iter = (s.find(iter->substr(0 ,iter->find(kDelimiter))) != s.end()) ?
l.erase(iter) : ++iter
);
WriteDataToFile(kF2, l.begin(), l.end());
}
