제출 #409409

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
409409		LptN21	Savrsen (COCI17_savrsen)	C++14	120 / 120	1293 ms	39416 KiB

savrsen

#include <bits/stdc++.h>
using namespace std;
#define fastIO ios_base::sync_with_stdio(false), cin.tie(NULL), cout.tie(NULL);
#define FF first
#define SS second
#define pb push_back
#define sz(x) (int)x.size()
#define oo 1e15
#define eps 1e-9
#define PI acos(-1.0)
#define lb lower_bound
#define ub upper_bound
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> ii;
const int N = 1e7+7, M=20+7;
const int MOD = 1e9+7;

int n, m, k, t;

int p[N];

signed main() {
    //freopen("test.inp", "r", stdin);
    //freopen("test.out", "w", stdout);
    //fastIO;
    scanf("%d%d", &m, &n);ll ans=0;m--;
    memset(p, 0, sizeof(int)*(n+1));
    for(int i=1;i<=n;i++) {
        for(int j=((m/i)+1)*i;j<=n;j+=i)
            p[j]+=i;
        if(p[i]) ans+=abs(2*i-p[i]);
    }
    printf("%lld", ans);
    return 0;
}
/* stuff you should look for
    - int overflow, array bounds
    - special cases (n=1?)
    - do smth instead of do nothing and stay organized
    - WRITE STUFF DOWN
    - DONT JUST STICK ON ONE APPROACH
*/

컴파일 시 표준 에러 (stderr) 메시지

savrsen.cpp: In function 'int main()':
savrsen.cpp:27:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   27 |     scanf("%d%d", &m, &n);ll ans=0;m--;
      |     ~~~~~^~~~~~~~~~~~~~~~

• Subtask 1: 120 / 120