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algorithm-template/segment-tree/3479 fruits-into-baskets-III.cpp

64 lines
1.9 KiB
C++

/* You are given two arrays of integers, fruits and baskets, each of length n, where fruits[i] represents the quantity of the ith type of fruit, and baskets[j] represents the capacity of the jth basket.
From left to right, place the fruits according to these rules:
1.Each fruit type must be placed in the leftmost available basket with a capacity greater than or equal to the quantity of that fruit type.
2.Each basket can hold only one type of fruit.
3.If a fruit type cannot be placed in any basket, it remains unplaced.
Return the number of fruit types that remain unplaced after all possible allocations are made.
*/
class SegmentTree {
private:
vector<int> segVal;
void maintain(int node) {
segVal[node] = max(segVal[node * 2], segVal[node * 2 + 1]);
}
void build(const vector<int>& vec, int node, int left, int right) {
if (left == right) {
segVal[node] = vec[left];
return;
}
int mid = (left + right) / 2;
build(vec, node * 2, left, mid);
build(vec, node * 2 + 1, mid + 1, right);
maintain(node);
}
public:
SegmentTree(const vector<int>& vec) {
size_t n = vec.size();
segVal.resize(2 << std::bit_width(n - 1));
build(vec, 1, 0, n - 1);
}
int findFirstAndUpdate(int node, int left, int right, int val) {
if (segVal[node] < val) {
return -1; // not found;
}
if (left == right) {
segVal[node] = -1; // update state
return left;
}
int mid = (left + right) / 2;
int idx = findFirstAndUpdate(node * 2, left, mid, val);
if (idx < 0) {
idx = findFirstAndUpdate(node * 2 + 1, mid + 1, right, val);
}
maintain(node);
return idx;
}
};
class Solution {
public:
int numOfUnplacedFruits(vector<int>& fruits, vector<int>& baskets) {
SegmentTree t(baskets);
int n = baskets.size(), ans = 0;
for (int x : fruits) {
if (t.findFirstAndUpdate(1, 0, n - 1, x) < 0) {
ans++;
}
}
return ans;
}
};