Bzoj3544 [ontak2010] creative accounting

If you don't understand the question, you can't write a little like a human voice. I'll go...

 

The question is to find a range to maximize the Sigma AI mod m value.

So... Just get the prefix and get greedy.

 

First obtain the prefix and S of the number of I, and then update the solution with S.

It is also possible that the prefix and S1 of the previous section are the smallest and larger than S in mod m. Then the sum of M + S-S1 is used to update the solution.

 

 1 /************************************************************** 2     Problem: 3544 3     User: rausen 4     Language: C++ 5     Result: Accepted 6     Time:2056 ms 7     Memory:7012 kb 8 ****************************************************************/ 9  10 #include <cstdio>11 #include <algorithm>12 #include <set>13  14 using namespace std;15 typedef long long ll;16 int n;17 ll mod, s, a, ans, p;18 set <ll> S;19  20 inline ll read(){21     ll x = 0, sgn = 1;22     char ch = getchar();23     while (ch < ‘0‘ || ch > ‘9‘){24         if (ch == ‘-‘) sgn = -1;25         ch = getchar();26     }27     while (ch >= ‘0‘ && ch <= ‘9‘){28         x = (ll) x * 10 + ch - ‘0‘;29         ch = getchar();30     }31     return sgn * x;32 }33  34 int main(){35     scanf("%d", &n); mod = read();36     for (int i = 1; i <= n; ++i){37         a = read();38         if (a < 0) a += (abs(a / mod) + 1) * mod;39         s += a, s %= mod;40         ans = max(ans, s);41         if (S.upper_bound(s) != S.end()){42             p = *(S.upper_bound(s));43             ans = max(ans, (s + mod - p) % mod);44         }45         S.insert(s);46     }47     printf("%lld\n", ans);48     return 0;49 }

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(P.s. shamelessly I used set again ...)

Bzoj3544 [ontak2010] creative accounting