Data file pattern matching algorithm?

See more:

C++

C

hi,Im having two data files in the format of integer,then want to match this data files using pattern matching,want to display common data in that two files.I need the C or C++ code.

FILE *datafile1;
datafile1 = fopen( "c:\\pw1.txt", "r" );
float fFiledata;
int nCount = 0;
int nLatitude[ 600 ];
int nLongitude[ 600 ];
float fHeight[ 600 ];
FILE *datafile1;
fscanf(datafile1,"%f",&fFiledata );
datafile2 = fopen( "c:\\pw2.txt", "r" );
float fFiledata;
int mCount = 0;
int mLatitude[ 600 ];
int mLongitude[ 600 ];
float fHeight2[ 600 ];
fscanf(datafile2,"%f",&fFiledata );

after that how to match this files find common data and store in another file ie datafile3?