leetcode

1 Random Problem

2 files changed, 35 insertions(+), 0 deletions(-)

diff --git a/ Problems/2013.cpp b/ Problems/2013.cpp

@@ -0,0 +1,34 @@

class DetectSquares {

using point_t = tuple<int, int>;

unordered_map<int, unordered_set<int>> ys;

static int cnt[1001][1001];

public:

DetectSquares() { memset(cnt, 0x00, sizeof(cnt)); }

void add(const vector<int> &point) {

const int x = point[0];

const int y = point[1];

cnt[x][y]++;

ys[x].insert(y);

}

int count(const vector<int> &point) {

const int x = point[0];

const int y = point[1];

int res = 0;

for (const auto yp : ys[point[0]]) {

const int len = abs(y - yp);

if (!len) continue;

if (x + len <= 1000) res += cnt[x][yp] * cnt[x + len][y] * cnt[x + len][yp];

if (x >= len) res += cnt[x][yp] * cnt[x - len][y] * cnt[x - len][yp];

}

return res;

}

};

int DetectSquares::cnt[1001][1001];

diff --git a/ README.md b/ README.md

@@ -1047,6 +1047,7 @@ for solving problems. | 2001 | Medium | [Number of Pairs of Interchangeable Rectangles](Problems/2001.cpp) | | 2002 | Medium | [Maximum Product of the Length of Two Palindromic Subsequences](Problems/2002.cpp) | | 2009 | Hard | [Minimum Number of Operations to Make Array Continuous](Problems/2009.cpp) |

| 2013 | Medium | [Detect Squares](Problems/2013.cpp) |

| 2023 | Medium | [Number of Pairs of Strings With Concatenation Equal to Target](Problems/2023.cpp) | | 2024 | Medium | [Maximize the Confusion of an Exam](Problems/2024.cpp) | | 2033 | Medium | [Minimum Operations to Make a Uni-Value Grid](Problems/2033.cpp) |