leetcode

2 Random Problems

3 files changed, 51 insertions(+), 0 deletions(-)

diff --git a/ Problems/0907.cpp b/ Problems/0907.cpp

@@ -0,0 +1,20 @@

class Solution {

static const int MOD = 1e9 + 7;

public:

int sumSubarrayMins(const vector<int> &arr) {

const int n = arr.size();

stack<int> st;

long long res = 0;

for (int right = 0, mid, left; right <= n; right++) {

while (!st.empty() && (right == n || arr[st.top()] > arr[right])) {

mid = st.top(), st.pop();

left = st.empty() ? -1 : st.top();

res = (res + (long long)arr[mid] * (right - mid) * (mid - left)) % MOD;

}

st.push(right);

}

return res;

}

};

diff --git a/ Problems/2104.cpp b/ Problems/2104.cpp

@@ -0,0 +1,29 @@

class Solution {

public:

long long subArrayRanges(const vector<int> &nums) {

const int n = nums.size();

long long res = 0;

stack<int> st;

for (int right = 0, mid, left; right <= n; right++) {

while (!st.empty() && (right == n || nums[st.top()] >= nums[right])) {

mid = st.top(), st.pop();

left = st.empty() ? -1 : st.top();

res -= (long long)nums[mid] * (right - mid) * (mid - left);

}

st.push(right);

}

st.pop();

for (int right = 0, mid, left; right <= n; right++) {

while (!st.empty() && (right == n || nums[st.top()] <= nums[right])) {

mid = st.top(), st.pop();

left = st.empty() ? -1 : st.top();

res += (long long)nums[mid] * (right - mid) * (mid - left);

}

st.push(right);

}

return res;

}

};

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

@@ -446,6 +446,7 @@ for solving problems. | 0901 | Medium | [Online Stock Span](Problems/0901.cpp) | | 0904 | Medium | [Fruit Into Baskets](Problems/0904.cpp) | | 0905 | Easy | [Sort Array By Parity](Problems/0905.cpp) |

| 0907 | Medium | [Sum of Subarray Minimums](Problems/0907.cpp) |

| 0909 | Medium | [Snakes and Ladders](Problems/0909.cpp) | | 0912 | Medium | [Sort an Array](Problems/0912.cpp) | | 0915 | Medium | [Partition Array into Disjoint Intervals](Problems/0915.cpp) |

@@ -745,6 +746,7 @@ for solving problems. | 2090 | Medium | [K Radius Subarray Averages](Problems/2090.cpp) | | 2095 | Medium | [Delete the Middle Node of a Linked List](Problems/2095.cpp) | | 2101 | Medium | [Detonate the Maximum Bombs](Problems/2101.cpp) |

| 2104 | Medium | [Sum of Subarray Ranges](Problems/2104.cpp) |

| 2115 | Medium | [Find All Possible Recipes from Given Supplies](Problems/2115.cpp) | | 2120 | Medium | [Execution of All Suffix Instructions Staying in a Grid](Problems/2120.cpp) | | 2125 | Medium | [Number of Laser Beams in a Bank](Problems/2125.cpp) |