Merge branch 'master' of github.com:baxiang/leetcode-go

Author: baxiang

443string-compression/main.go

@@ -0,0 +1,33 @@
+package main
+
+import (
+	"fmt"
+	"strconv"
+)
+
+func compress(chars []byte) int {
+	var anchor = 0
+	var write = 0
+	for read := 0; read < len(chars); read++ {
+		if read+1 == len(chars) || chars[read+1] != chars[read] {
+			chars[write] = chars[anchor]
+			write++
+			if read > anchor {
+				char := strconv.Itoa(read - anchor + 1)
+				for i := 0; i < len(char); i++ {
+					chars[write] = char[i]
+					write++
+				}
+			}
+			anchor = read + 1
+		}
+	}
+	return write
+}
+
+func main() {
+	fmt.Println(compress([]byte{'a', 'a', 'a', 'b', 'b'}))
+	fmt.Println(compress([]byte{'a','a','b','b','c','c','c'}))
+	fmt.Println(compress([]byte{'a'}))
+	fmt.Println(compress([]byte{'a','b','b','b','b','b','b','b','b','b','b','b','b'}))
+}

84largest-rectangle-in-histogram/main.go

@@ -0,0 +1,25 @@
+package main
+
+import "fmt"
+
+func largestRectangleArea(heights []int) int {
+	var res int
+	for i := 0; i < len(heights); i++ {
+		var min = heights[i]
+		for j := i; j < len(heights); j++ {
+			if min > heights[j] {
+				min = heights[j]
+			}
+			width := j - i + 1
+			area := min * width
+			if area > res {
+				res = area
+			}
+		}
+	}
+	return res
+}
+
+func main() {
+	fmt.Println(largestRectangleArea([]int{2, 1, 5, 6, 2, 3}))
+}

974subarray-sums-divisible-by-k/main.go

@@ -0,0 +1,38 @@
+package main
+
+import "fmt"
+
+func subarraysDivByK1(A []int, K int) int {
+	var res int
+	for i := 0; i < len(A); i++ {
+		var sum =0
+		for j := i ; j <len(A); j++ {
+			sum +=A[j]
+			if sum%K == 0 {
+				res++
+			}
+		}
+	}
+	return res
+}
+func subarraysDivByK(A []int, K int) int {
+	record := map[int]int{0: 1} // 如果A中有元素能整除K， 那么相关元素单独能构成符合题意的子数组，需要统计
+	prefixSum, result := 0, 0
+	for i := 0; i < len(A); i++ {
+		prefixSum += A[i]
+		mod := (prefixSum % K+K)%K
+		//if mod < 0 { // prefixSum可能是负数，导致mod为负数， 取余的结果mod为负，跟取余结果为mod+K是等价的
+		//	mod += K
+		//}
+		fmt.Println(mod)
+		result += record[mod]
+		record[mod]++
+	}
+	return result
+}
+
+
+func main() {
+	subarraysDivByK([]int{4, 5, 0, -2, -3, 1}, 5)
+	fmt.Println()
+}