#include <iostream>
#include <utility>

const std::size_t NROWS = 5, NCOLS = 3 ;

// return true on success, with row,col set to the indices
// return false if not found, with row set to NROWS,col set to NCOLS
bool find_1( const int array[NROWS][NCOLS], int value, std::size_t& row, std::size_t& col )
{
    for( row = 0 ; row < NROWS ; ++row )
        for( col = 0 ; col < NCOLS ; ++col )
            if( array[row][col] == value ) return true ;

    return false ; // not fomd, row == NROWS, col == NCOLS
}

// return a pair of row, col indices on success
// returen the pair NROWS,NCOLS if not found
std::pair<std::size_t,std::size_t> find_2( const int array[NROWS][NCOLS], int value )
{
    for( std::size_t row = 0 ; row < NROWS ; ++row )
        for( std::size_t col = 0 ; col < NCOLS ; ++col )
            if( array[row][col] == value ) return { row, col } ;

    return { NROWS, NCOLS } ; // not fomd, return pair NROWS,NCOLS
}


// return offset from array[0][0] on success
// return NROWS * NCOLS if not found
std::size_t find_3( const int array[NROWS][NCOLS], int value )
{
    const std::size_t BEYOND = NROWS * NCOLS ;
    for( std::size_t pos = 0 ; pos < BEYOND ; ++pos )
        if( array[0][pos] == value ) return pos ;
    return BEYOND ; // not found
}

int main()
{
    const int a[NROWS][NCOLS]
    {
        {  0,  1,  2 },
        {  3,  4,  5 },
        {  6,  7,  8 },
        {  9, 10, 11 },
        { 12, 13, 14 },
    };

    std::size_t row, col ;

    if( find_1( a, 7, row, col ) )
        std::cout << "found " << a[row][col] << " at " << row << ',' << col << '\n' ;

    const auto p = find_2( a, 7 ) ;
    row = p.first ;
    col = p.second ;
    if( row < NROWS )
        std::cout << "found " << a[row][col] << " at " << row << ',' << col << '\n' ;

    const auto offset = find_3( a, 7 ) ;
    if( offset < NROWS*NCOLS )
        std::cout << "found " << a[0][offset] << " at offset " << offset << '\n' ;
}