add new solutions

solutions/34/q3454/solution.go

@@ -0,0 +1,85 @@
+package q3454
+
+import (
+	"math"
+	"slices"
+)
+
+type void struct{}
+
+func calcLengthAtY(squares [][]int) [][2]int {
+	vertIdx := make([][2]int, len(squares)*2)
+	for i := range squares {
+		vertIdx[i*2] = [2]int{squares[i][1], i}
+		vertIdx[i*2+1] = [2]int{squares[i][1] + squares[i][2], i}
+	}
+	slices.SortFunc(vertIdx, func(a, b [2]int) int { return a[0] - b[0] })
+
+	curSq := map[int]void{}
+	curLenBuf := make([][2]int, len(squares))
+
+	calcLen := func() int {
+		curLen := 0
+		curLenBuf = curLenBuf[:0]
+		for i := range curSq {
+			l := squares[i][0]
+			r := l + squares[i][2]
+			curLenBuf = append(curLenBuf, [2]int{l, r})
+		}
+		slices.SortFunc(curLenBuf, func(a, b [2]int) int { return a[0] - b[0] })
+		r := math.MinInt
+		for i := range curLenBuf {
+			if curLenBuf[i][0] < r {
+				curLen += max(0, curLenBuf[i][1]-r)
+			} else {
+				curLen += curLenBuf[i][1] - curLenBuf[i][0]
+			}
+			r = max(r, curLenBuf[i][1])
+		}
+		return curLen
+	}
+
+	ret := make([][2]int, 0, len(squares)*2)
+	for i := 0; i < len(vertIdx); {
+		curY := vertIdx[i][0]
+		for ; i < len(vertIdx) && vertIdx[i][0] == curY; i++ {
+			sq := vertIdx[i][1]
+			if _, ok := curSq[sq]; ok {
+				delete(curSq, sq)
+			} else {
+				curSq[sq] = void{}
+			}
+		}
+
+		ret = append(ret, [2]int{curY, calcLen()})
+	}
+	return ret
+}
+
+func separateSquares(squares [][]int) float64 {
+	lenAtY := calcLengthAtY(squares)
+
+	totalArea := 0
+	for i := 0; i < len(lenAtY)-1; i++ {
+		totalArea += lenAtY[i][1] * (lenAtY[i+1][0] - lenAtY[i][0])
+	}
+
+	var area int
+	for i := 0; i < len(lenAtY)-1; i++ {
+		y, nextY := lenAtY[i][0], lenAtY[i+1][0]
+		l := lenAtY[i][1]
+
+		areaT := (nextY-y)*l + area
+		switch {
+		case areaT*2 == totalArea:
+			return float64(nextY)
+		case areaT*2 > totalArea:
+			needed := float64(totalArea-area*2) / 2
+			return float64(y) + needed/float64(l)
+		}
+		area = areaT
+	}
+	return -1
+}
+
+var _ = separateSquares