Educational Codeforces Round 10

A:Gabriel and Caterpillar

题意：蜗牛爬树问题；值得一提的是在第n天如果恰好在天黑时爬到END，则恰好整除，不用再+1；

day = (End - Begin - day0)/(12*(up-down))+1;

#include <iostream>
#include <algorithm>
#include <stdlib.h>
#include <time.h>
#include <cmath>
#include <cstdio>
#include <string>
#include <cstring>
#include <vector>
#include <queue>
#include <stack>
#include <set>

#define c_false ios_base::sync_with_stdio(false); cin.tie(0)
#define INF 0x3f3f3f3f
#define INFL 0x3f3f3f3f3f3f3f3f
#define zero_(x,y) memset(x , y , sizeof(x))
#define zero(x) memset(x , 0 , sizeof(x))
#define MAX(x) memset(x , 0x3f ,sizeof(x))
#define swa(x,y) {LL s;s=x;x=y;y=s;}
using namespace std ;
#define N 50005

const double PI = acos(-1.0);
typedef long long LL ;

int main(){
    //freopen("in.txt","r",stdin);
    //freopen("out.txt","w",stdout);
    //ios_base::sync_with_stdio(false); cin.tie(0);
    int Begin, End, up, down;
    scanf("%d%d%d%d", &Begin, &End, &up, &down);
    int day0 = 8*up;
    int day;
    if(up-down <= 0){
        if(End - Begin - day0 <=0) day = 0;
        else day = -1;
    }else{
        if(End - Begin - day0 <=0) day = 0;
        else {
            if((End - Begin - day0)%(12*(up-down)) == 0)
                day = (End - Begin - day0)/(12*(up-down));
            else
                day = (End - Begin - day0)/(12*(up-down))+1;
        }
    }
    cout<<day;
    return 0;
}

View Code