hdu 4950 Monster--2014 Multi-University Training Contest 8

链接：http://acm.hdu.edu.cn/showproblem.php?pid=4950

Monster

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others)
Total Submission(s): 260    Accepted Submission(s): 114

Problem Description

Teacher Mai has a kingdom. A monster has invaded this kingdom, and Teacher Mai wants to kill it.

Monster initially has h HP. And it will die if HP is less than 1.

Teacher Mai and monster take turns to do their action. In one round, Teacher Mai can attack the monster so that the HP of the monster will be reduced by a. At the end of this round, the HP of monster will be increased by b.

After k consecutive round's attack, Teacher Mai must take a rest in this round. However, he can also choose to take a rest in any round.

Output "YES" if Teacher Mai can kill this monster, else output "NO".

 

Input

There are multiple test cases, terminated by a line "0 0 0 0".

For each test case, the first line contains four integers h,a,b,k(1<=h,a,b,k <=10^9).

 

Output

For each case, output "Case #k: " first, where k is the case number counting from 1. Then output "YES" if Teacher Mai can kill this monster, else output "NO".

 

Sample Input

5 3 2 20 0 0 0

 

Sample Output

Case #1: NO

 

Source

2014 Multi-University Training Contest 8

 

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这是这场的签到题。没啥好解释的。不过情况稍微有点复杂，一个个分析就完了。

#include<iostream>#include<cstring>#include<cstdio>using namespace std;int main(){    int kase=0;    long long h,a,b,k;    while(cin>>h>>a>>b>>k){        if(h==0 && a==0 && b==0 && k==0){            break;        }        if(h<=a){            printf("Case #%d: YES\n",++kase);            continue;        }        if(a<=b){            printf("Case #%d: NO\n",++kase);            continue;        }        if((a-b)*k>=(h-b)){            printf("Case #%d: YES\n",++kase);            continue;        }        if((a-b)*k-b>0){            printf("Case #%d: YES\n",++kase);            continue;        }        else{            printf("Case #%d: NO\n",++kase);        }    }    return 0;}