Submission #668810

#	Time	Username	Problem	Language	Result	Execution time	Memory
668810		vuavisao	Modsum (NOI12_modsum)	C++14	25 / 25	1 ms	340 KiB

modsum

#include<bits/stdc++.h>
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#define ll long long
using namespace std;

const int N = 1e3 + 10;

int n;
int a[N], b[N];

int dp[N][10];
int res;

int32_t main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    if (fopen("sum.inp", "r")) {
        freopen("sum.inp", "r", stdin);
        freopen("sum.out", "w", stdout);
    }
    cin >> n;
    for(int i = 1; i <= n; ++ i) cin >> a[i] >> b[i];
    dp[0][0] = 1;
    for(int i = 0; i < n; ++ i) {
        for(int j = 0; j < 5; ++ j) {
            if(dp[i][j] == 0) continue;
            for(int k = a[i + 1]; k <= b[i + 1]; ++ k) dp[i + 1][(j + k) % 5] += dp[i][j];
        }
    }
    int res = 0;
    auto sqr = [&] (int val) { return val * val; };
    for(int i = 0; i < 5; ++ i) {
        int sqr_i = sqr(i);
        int double_sqr_i = sqr(sqr_i);
        res += dp[n][i] * ((double_sqr_i + 2 * sqr_i) % 5 + 1);
    }
    cout << res;
    return 0;
}

/// Code by vuavisao

Compilation message (stderr)

modsum.cpp: In function 'int32_t main()':
modsum.cpp:20:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   20 |         freopen("sum.inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
modsum.cpp:21:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   21 |         freopen("sum.out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 5 / 5
• Subtask 3: 5 / 5
• Subtask 4: 5 / 5
• Subtask 5: 5 / 5