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| class Solution {
public int countNicePairs(int[] nums) {
int nicePairs = 0;
Map<Integer, Integer> countMap = new HashMap<>();
for (int num : nums) {
int key = num - rev(num);
int count = countMap.getOrDefault(key, 0);
nicePairs += count;
nicePairs %= 1000000000 + 7;
countMap.put(key, count + 1);
}
return nicePairs;
}
private int rev(int num) {
int res = 0;
while (num > 0) {
res = res * 10 + num % 10;
num /= 10;
}
return res;
}
}
|
References
1814. Count Nice Pairs in an Array