concept of map, freq and SOE
Intuition\n Describe your first thoughts on how to solve this problem. \n\n# Approach\n Describe your approach to solving the problem. \n\n# Complexity\n- Time 
# Intuition\n<!-- Describe your first thoughts on how to solve this problem. -->\n\n# Approach\n<!-- Describe your approach to solving the problem. -->\n\n# Complexity\n- Time complexity:\n<!-- Add your time complexity here, e.g. $$O(n)$$ -->\n\n- Space complexity:\n<!-- Add your space complexity here, e.g. $$O(n)$$ -->\n\n# Code\n```\n#define ll long long int\nclass Solution {\npublic:\n    int sumOfFlooredPairs(vector<int>& nums) {\n        ll mx = 1e5;\n        vector<ll> freq(mx+2, 0), pref(mx+2, 0);\n        for(auto itr : nums) freq[itr]++;\n        for(ll i=1;i<=mx;i++) pref[i]=pref[i-1]+freq[i];\n\n        ll ans = 0;\n        ll MOD = 1e9+7;\n        for(ll i=1;i<=mx;i++){\n            ll cnt = 1;\n            for(ll j=i;j<=mx;j+=i){\n                ll st = j;\n                ll en = j+i-1;\n                en = min(mx, en);\n                ll sx = ((pref[en]-pref[st-1])*cnt)%MOD;\n                sx = (sx*freq[i])%MOD;\n                ans+=sx;\n                ans%=MOD;\n                cnt++;\n            }\n        }\n        return ans;\n    }\n};\n```
['C++']