update

Author: ldeng7

000xx/01.go renamed to 01xxxx/0001.go

@@ -0,0 +1,34 @@
+func longestPalindrome(s string) string {
+	if 0 == len(s) {
+		return ""
+	}
+	t := []byte{'#'}
+	for _, c := range []byte(s) {
+		t = append(t, c)
+		t = append(t, '#')
+	}
+
+	m, mi := 0, 0
+	for i := 0; i < len(t); i++ {
+		k := i
+		if len(t)-i-1 < k {
+			k = len(t) - i - 1
+		}
+		j := 1
+		for ; j <= k; j++ {
+			if t[i+j] != t[i-j] {
+				break
+			}
+		}
+		if j > m {
+			m, mi = j, i
+		}
+	}
+	var i int
+	if mi&1 == 1 {
+		i = mi/2 + 1 - m/2
+	} else {
+		i = mi/2 - m/2
+	}
+	return s[i : i+m-1]
+}

000xx/02.go renamed to 01xxxx/0002.go

@@ -0,0 +1,17 @@
+func convert(s string, numRows int) string {
+	if numRows <= 1 {
+		return s
+	}
+	out := []byte{}
+	n := (numRows - 1) * 2
+	for i := 0; i < numRows; i++ {
+		for j := i; j < len(s); j += n {
+			out = append(out, s[j])
+			k := j + n - i*2
+			if i > 0 && i < numRows-1 && k < len(s) {
+				out = append(out, s[k])
+			}
+		}
+	}
+	return string(out)
+}

000xx/03.go renamed to 01xxxx/0003.go

@@ -0,0 +1,31 @@
+func reverse(x int) int {
+	m := false
+	if x < 0 {
+		m = true
+		x = -x
+	}
+	ds := []int{}
+	for x > 0 {
+		ds = append(ds, x%10)
+		x /= 10
+	}
+	o := 0
+	b := 1
+	for i := len(ds) - 1; i >= 0; i-- {
+		o += ds[i] * b
+		b *= 10
+		if !m {
+			if o >= 2147483648 {
+				return 0
+			}
+		} else {
+			if o > 2147483648 {
+				return 0
+			}
+		}
+	}
+	if m {
+		o = -o
+	}
+	return o
+}

01xxxx/0005.go

@@ -0,0 +1,62 @@
+func myAtoi(str string) int {
+	ds := []byte{}
+	m := false
+	started := false
+	for _, c := range []byte(str) {
+		if c == ' ' {
+			if started {
+				break
+			}
+			continue
+		} else if c == '+' || c == '-' {
+			if !started {
+				started = true
+				m = c == '-'
+				continue
+			}
+			break
+		} else if c < '0' || c > '9' {
+			break
+		}
+		started = true
+		ds = append(ds, c)
+	}
+
+	dst := []byte{}
+	started = false
+	for _, c := range ds {
+		if c == '0' && !started {
+			continue
+		}
+		started = true
+		dst = append(dst, c)
+	}
+	ds = dst
+	if len(ds) > 11 {
+		if !m {
+			return 2147483647
+		} else {
+			return -2147483648
+		}
+	}
+
+	var o, b uint64 = 0, 1
+	for i := len(ds) - 1; i >= 0; i-- {
+		o += uint64(ds[i]-'0') * b
+		b *= 10
+		if !m {
+			if o >= 2147483648 {
+				return 2147483647
+			}
+		} else {
+			if o > 2147483648 {
+				return -2147483648
+			}
+		}
+	}
+	i := int(o)
+	if m {
+		i = -i
+	}
+	return i
+}

01xxxx/0006.go

@@ -0,0 +1,7 @@
+func intToRoman(num int) string {
+	t := []string{"", "M", "MM", "MMM"}
+	h := []string{"", "C", "CC", "CCC", "CD", "D", "DC", "DCC", "DCCC", "CM"}
+	d := []string{"", "X", "XX", "XXX", "XL", "L", "LX", "LXX", "LXXX", "XC"}
+	u := []string{"", "I", "II", "III", "IV", "V", "VI", "VII", "VIII", "IX"}
+	return t[num/1000] + h[(num%1000)/100] + d[(num%100)/10] + u[num%10]
+}