find.go

// Package bench is a package which contains
// programs of Go Benchmark Competition.
package bench
 
import (
	"bufio"
	"errors"
	"os"
	"strconv"
)
 
// Find reads the text file on the `path`,
// finds the `s` words on the file and
// returns the row numbers and indices
// in the form of `r:c,r:c,...r:c`,
// at which the `s` word exists.
func Find(path, s string) (string, error) {
	// TODO: Implement this function.
	if len(s) == 0 {
		return "", errors.New("len of S is equal to zero")
	}
	fd, _ := os.Open(path)
	sLen := len(s)
	scanner := bufio.NewScanner(fd)
	resp := ""
	i := 1
	f := 0
	for scanner.Scan() {
		is := strconv.Itoa(i)
		line := scanner.Bytes()
		for cntr := 0; cntr+sLen < len(line); cntr++ {
			if string(line[cntr:cntr+sLen]) == s {
				cs := strconv.Itoa(cntr)
				if f != 0 {
					resp += ("," + is + ":" + cs)
				} else {
					resp += (is + ":" + cs)
					f = 1
				}
			}
		}
		i++
	}
	return resp, nil
}