https://pintia.cn/problem-sets/994805260223102976/problems/994805260780945408
0也是差值,否则12测试点不过
#include <iostream>
#include <cmath>
using namespace std;
int main(){
int n, num, cha[10002] = {0}, max = 0;
cin >> n;
for(int i = 1; i <= n; i++){
cin >> num;
cha[abs(num-i)]++;
if(abs(num-i) > max) max = abs(num-i);
}
for(int i = max; i >= 0; i--){
if(cha[i] > 1)
cout << i << " " << cha[i] << endl;
}
}