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-rw-r--r--num_bad_pairs.cpp27
1 files changed, 27 insertions, 0 deletions
diff --git a/num_bad_pairs.cpp b/num_bad_pairs.cpp
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--- /dev/null
+++ b/num_bad_pairs.cpp
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+#include "leetcode.h"
+
+/*
+ * given: 0-indexed integer array
+ * bad pair: (i, j) if
+ * i < j && j - i != nums[j] - nums[i]
+ */
+
+class Solution {
+public:
+ long long countBadPairs(vector<int> &nums) {
+ long long ans = 0;
+ unordered_map<int, int> um;
+ for (int i = 0; i < nums.size(); ++i) {
+ ans += (long long)i - um[nums[i] - i];
+ ++um[nums[i] - i];
+ }
+ return ans;
+ }
+};
+
+int main() {
+ Solution obj;
+ vector<int> nums1 = {4, 1, 3, 3}, nums2 = {1, 2, 3, 4, 5};
+ cout << obj.countBadPairs(nums1) << endl; // expect: 5
+ cout << obj.countBadPairs(nums2) << endl; // expect: 0
+}