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Jul 9, 2024
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[pull] main from doocs:main #157

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109 changes: 77 additions & 32 deletions solution/0700-0799/0702.Search in a Sorted Array of Unknown Size/README.md
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Original file line number Diff line number Diff line change
Expand Up @@ -70,7 +70,13 @@ tags:

<!-- solution:start -->

### 方法一
### 方法一：二分查找

我们先定义一个指针 $r = 1$，每一次判断 $r$ 处的值是否小于目标值，如果小于目标值，我们将 $r$ 乘以 $2$，即左移一位，直到 $r$ 处的值大于等于目标值。此时，我们可以确定目标值在 $[r / 2, r]$ 的区间内。

接下来，我们定义一个指针 $l = r / 2$，然后我们可以使用二分查找的方法在 $[l, r]$ 的区间内查找目标值的位置。

时间复杂度 $O(\log M)$，其中 $M$ 为目标值的位置。空间复杂度 $O(1)$。

<!-- tabs:start -->

Expand All @@ -86,20 +92,18 @@ tags:


class Solution:
def search(self, reader, target):
"""
:type reader: ArrayReader
:type target: int
:rtype: int
"""
left, right = 0, 20000
while left < right:
mid = (left + right) >> 1
def search(self, reader: "ArrayReader", target: int) -> int:
r = 1
while reader.get(r) < target:
r <<= 1
l = r >> 1
while l < r:
mid = (l + r) >> 1
if reader.get(mid) >= target:
right = mid
r = mid
else:
left = mid + 1
return left if reader.get(left) == target else -1
l = mid + 1
return l if reader.get(l) == target else -1
```

#### Java
Expand All @@ -115,16 +119,20 @@ class Solution:

class Solution {
public int search(ArrayReader reader, int target) {
int left = 0, right = 20000;
while (left < right) {
int mid = left + right >> 1;
int r = 1;
while (reader.get(r) < target) {
r <<= 1;
}
int l = r >> 1;
while (l < r) {
int mid = (l + r) >> 1;
if (reader.get(mid) >= target) {
right = mid;
r = mid;
} else {
left = mid + 1;
l = mid + 1;
}
}
return reader.get(left) == target ? left : -1;
return reader.get(l) == target ? l : -1;
}
}
```
Expand All @@ -144,16 +152,20 @@ class Solution {
class Solution {
public:
int search(const ArrayReader& reader, int target) {
int left = 0, right = 20000;
while (left < right) {
int mid = left + right >> 1;
int r = 1;
while (reader.get(r) < target) {
r <<= 1;
}
int l = r >> 1;
while (l < r) {
int mid = (l + r) >> 1;
if (reader.get(mid) >= target) {
right = mid;
r = mid;
} else {
left = mid + 1;
l = mid + 1;
}
}
return reader.get(left) == target ? left : -1;
return reader.get(l) == target ? l : -1;
}
};
```
Expand All @@ -171,22 +183,55 @@ public:
*/

func search(reader ArrayReader, target int) int {
left, right := 0, 20000
for left < right {
mid := (left + right) >> 1
r := 1
for reader.get(r) < target {
r <<= 1
}
l := r >> 1
for l < r {
mid := (l + r) >> 1
if reader.get(mid) >= target {
right = mid
r = mid
} else {
left = mid + 1
l = mid + 1
}
}
if reader.get(left) == target {
return left
if reader.get(l) == target {
return l
}
return -1
}
```

#### TypeScript

```ts
/**
* class ArrayReader {
* // This is the ArrayReader's API interface.
* // You should not implement it, or speculate about its implementation
* get(index: number): number {};
* };
*/

function search(reader: ArrayReader, target: number): number {
let r = 1;
while (reader.get(r) < target) {
r <<= 1;
}
let l = r >> 1;
while (l < r) {
const mid = (l + r) >> 1;
if (reader.get(mid) >= target) {
r = mid;
} else {
l = mid + 1;
}
}
return reader.get(l) === target ? l : -1;
}
```

<!-- tabs:end -->

<!-- solution:end -->
Expand Down
109 changes: 77 additions & 32 deletions solution/0700-0799/0702.Search in a Sorted Array of Unknown Size/README_EN.md
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Original file line number Diff line number Diff line change
Expand Up @@ -65,7 +65,13 @@ tags:

<!-- solution:start -->

### Solution 1
### Solution 1: Binary Search

First, we define a pointer $r = 1$. Each time, we check if the value at position $r$ is less than the target value. If it is, we multiply $r$ by $2$, i.e., shift it left by one bit, until the value at position $r$ is greater than or equal to the target value. At this point, we can determine that the target value is within the interval $[r / 2, r]$.

Next, we define a pointer $l = r / 2$, and then we can use the binary search method to find the position of the target value within the interval $[l, r]$.

The time complexity is $O(\log M)$, where $M$ is the position of the target value. The space complexity is $O(1)$.

<!-- tabs:start -->

Expand All @@ -81,20 +87,18 @@ tags:


class Solution:
def search(self, reader, target):
"""
:type reader: ArrayReader
:type target: int
:rtype: int
"""
left, right = 0, 20000
while left < right:
mid = (left + right) >> 1
def search(self, reader: "ArrayReader", target: int) -> int:
r = 1
while reader.get(r) < target:
r <<= 1
l = r >> 1
while l < r:
mid = (l + r) >> 1
if reader.get(mid) >= target:
right = mid
r = mid
else:
left = mid + 1
return left if reader.get(left) == target else -1
l = mid + 1
return l if reader.get(l) == target else -1
```

#### Java
Expand All @@ -110,16 +114,20 @@ class Solution:

class Solution {
public int search(ArrayReader reader, int target) {
int left = 0, right = 20000;
while (left < right) {
int mid = left + right >> 1;
int r = 1;
while (reader.get(r) < target) {
r <<= 1;
}
int l = r >> 1;
while (l < r) {
int mid = (l + r) >> 1;
if (reader.get(mid) >= target) {
right = mid;
r = mid;
} else {
left = mid + 1;
l = mid + 1;
}
}
return reader.get(left) == target ? left : -1;
return reader.get(l) == target ? l : -1;
}
}
```
Expand All @@ -139,16 +147,20 @@ class Solution {
class Solution {
public:
int search(const ArrayReader& reader, int target) {
int left = 0, right = 20000;
while (left < right) {
int mid = left + right >> 1;
int r = 1;
while (reader.get(r) < target) {
r <<= 1;
}
int l = r >> 1;
while (l < r) {
int mid = (l + r) >> 1;
if (reader.get(mid) >= target) {
right = mid;
r = mid;
} else {
left = mid + 1;
l = mid + 1;
}
}
return reader.get(left) == target ? left : -1;
return reader.get(l) == target ? l : -1;
}
};
```
Expand All @@ -166,22 +178,55 @@ public:
*/

func search(reader ArrayReader, target int) int {
left, right := 0, 20000
for left < right {
mid := (left + right) >> 1
r := 1
for reader.get(r) < target {
r <<= 1
}
l := r >> 1
for l < r {
mid := (l + r) >> 1
if reader.get(mid) >= target {
right = mid
r = mid
} else {
left = mid + 1
l = mid + 1
}
}
if reader.get(left) == target {
return left
if reader.get(l) == target {
return l
}
return -1
}
```

#### TypeScript

```ts
/**
* class ArrayReader {
* // This is the ArrayReader's API interface.
* // You should not implement it, or speculate about its implementation
* get(index: number): number {};
* };
*/

function search(reader: ArrayReader, target: number): number {
let r = 1;
while (reader.get(r) < target) {
r <<= 1;
}
let l = r >> 1;
while (l < r) {
const mid = (l + r) >> 1;
if (reader.get(mid) >= target) {
r = mid;
} else {
l = mid + 1;
}
}
return reader.get(l) === target ? l : -1;
}
```

<!-- tabs:end -->

<!-- solution:end -->
Expand Down
16 changes: 10 additions & 6 deletions solution/0700-0799/0702.Search in a Sorted Array of Unknown Size/Solution.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -10,15 +10,19 @@
class Solution {
public:
int search(const ArrayReader& reader, int target) {
int left = 0, right = 20000;
while (left < right) {
int mid = left + right >> 1;
int r = 1;
while (reader.get(r) < target) {
r <<= 1;
}
int l = r >> 1;
while (l < r) {
int mid = (l + r) >> 1;
if (reader.get(mid) >= target) {
right = mid;
r = mid;
} else {
left = mid + 1;
l = mid + 1;
}
}
return reader.get(left) == target ? left : -1;
return reader.get(l) == target ? l : -1;
}
};
18 changes: 11 additions & 7 deletions solution/0700-0799/0702.Search in a Sorted Array of Unknown Size/Solution.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -8,17 +8,21 @@
*/

func search(reader ArrayReader, target int) int {
left, right := 0, 20000
for left < right {
mid := (left + right) >> 1
r := 1
for reader.get(r) < target {
r <<= 1
}
l := r >> 1
for l < r {
mid := (l + r) >> 1
if reader.get(mid) >= target {
right = mid
r = mid
} else {
left = mid + 1
l = mid + 1
}
}
if reader.get(left) == target {
return left
if reader.get(l) == target {
return l
}
return -1
}
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