26 lines
591 B
C++
26 lines
591 B
C++
#include <vector>
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#include <cstdio>
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#include <unordered_map>
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class Solution {
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public:
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static int fourSumCount(const std::vector<int>& nums1, const std::vector<int>& nums2, const std::vector<int>& nums3, const std::vector<int>& nums4) {
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int ret = 0;
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std::unordered_map<int, int> m1, m2;
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for (int i : nums1)
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for (int j : nums2)
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++m1[i + j];
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for (int i : nums3)
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for (int j : nums4)
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++m2[i + j];
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for (const auto& p : m1)
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ret += p.second * m2[-p.first];
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return ret;
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}
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};
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int main() {
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std::printf("%d\n", Solution::fourSumCount({0}, {0}, {0}, {0}));
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return 0;
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}
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