夢追い人

"It takes a dreamer to make a dream come true."―Vincent Willem van Gogh

9時だよ!全員集合!

ARC初回レーテッドコンテストの結果は・・・
3完34位タイでした。
あ、ICPC方式ね(たぶん

A

やるだけ

#include <cstdio>
int main() {
    int y; scanf("%d",&y);
    if (y%100==0&&y%400!=0) puts("NO");
    else if (y%4==0) puts("YES");
    else puts("NO");
}

B

「暦」で検索

#include <cstdio>
int y, m, d;
int day1[12]={31,28,31,30,31,30,31,31,30,31,30,31};
int day2[12]={31,29,31,30,31,30,31,31,30,31,30,31};
bool isreep(int y) {
    if (y%100==0&&y%400!=0) return false;
    if (y%4==0) return true;
    return false;
}
void next() {
    d++;
    if (isreep(y)) {
        if (day2[m-1]>=d) return;
        m++; d=1;
        if (m==13) { m=1; y++; }
    } else {
        if (day1[m-1]>=d) return;
        m++; d=1;
        if (m==13) { m=1; y++; }
    }
}
bool ok() {
    if ((double)y/(double)m/(double)d==y/m/d) return true;
    return false;
}
int main() {
    scanf("%d/%d/%d",&y,&m,&d);
    while (!ok()) next();
    printf("%d/%02d/%02d\n",y,m,d);
}

C

16通り書き出すだけ

#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
using namespace std;
string lr[16]={
"AA","BB","XX","YY",
"AB","BA","XY","YX",
"AX","XA","BX","XB",
"AY","YA","BY","YB"};
bool used[1000];
int main() {
    int n; scanf("%d",&n);
    string str; cin>>str;
    int res=10000;
    for (int p=0; p<16; p++) {
        for (int q=0; q<16; q++) {
            if (p==q) continue;
            string x="", y="";
            for (int i=0; i<n; i++){
                if (lr[p][0]!=str[i]) x+=str[i];
                else {
                    if (i+1<n&&lr[p][1]==str[i+1]) { x+='L'; i++; }
                    else x+=str[i];
                }
            }
            int len=x.length();
            for (int i=0; i<len; i++) {
                if (lr[q][0]!=x[i]) y+=x[i];
                else {
                    if (i+1<len&&lr[q][1]==x[i+1]) { y+='R'; i++; }
                    else y+=x[i];
                }
            }
            res=min(res, (int)y.length());
        }
    }
    printf("%d\n",res);
}

D

糞むずい

結果

#AtCoderこわちかよらんとこ