Codeforces Round #146 (Div. 2)
A 判断不同字母的个数为偶数还是奇数
#include <iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
int main()
{
int i,j,k,n,num[500];
memset(num,0,sizeof(num));
char str[201];
gets(str);
k = strlen(str);
for(i = 0 ; i < k ; i++)
num[str[i]]++;
int count = 0;
for(i = 0 ; i < 500 ; i++)
if(num[i])
count++;
if(count%2==0)
printf("CHAT WITH HER!\n");
else
printf("IGNORE HIM!");
return 0;
}
B题
求一个数的因数的个数公式
对一个数X分解质因子得 X = p1a1 *
p2a2 * p3a3 * ... pkak ，X的因子数为 (a1 + 1)*(a2 + 1)*(a3 + 1)*...*(ak + 1);
写的乱七八糟的
#include <iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<cmath>
using namespace std;
__int64 s,ss;
int num[1000001],dis[10000],pr[100000],pd[100000];
int main()
{
int a,b,c,i,j,k;
cin>>a>>b>>c;
for(i = 2; i <= 10000 ; i++)
{
if(!pr[i])
{
for(j = i+i ; j <= 10000 ; j+=i)
if(pr[j])
pr[j] = 1;
}
}
int g = 0;
for(i =2; i <= 10000 ; i++)
if(!pr[i])
pd[g++] = i;
s = 0;
for(i = 1; i <= a ; i++)
for(j = 1; j <= b ; j++)
for(k = 1; k <= c ; k++)
{
ss = i*j*k;
__int64 xx = ss;
if(!num[ss])
{
int y = 0,kk =0 ,tt = 1;
while(xx)
{
if(xx%pd[y]==0)
{
kk++;
xx = xx/pd[y];
}
else
{
tt = tt*(kk+1);
y++;
kk = 0;
}
if(xx==1)
break;
}
if(kk)
tt = tt*(kk+1);
num[ss] = tt;
}
s+=num[ss];
s = s%1073741824;
}
printf("%I64d\n",s);
return 0;
}
C题 直接枚举 忘用——int64了
View Code
1 #include <iostream> 2 #include<cstdio> 3 #include<cstring> 4 #include<algorithm> 5 #define INF 0xfffffff 6 using namespace std; 7 __int64 gcd(__int64 a,__int64 b) 8 { 9 return b==0?a:gcd(b,a%b); 10 } 11 int main() 12 { 13 int i,j,k,n; 14 __int64 s = 1,max = 0; 15 cin>>n; 16 if(n>200) 17 { 18 for(i = n-200 ; i <= n ; i++) 19 for(j = i ; j <= n ; j++) 20 for(k = j ; k <= n ; k++) 21 { 22 s = i/(gcd(i,j))*j; 23 s = s/(gcd(s,k))*k; 24 if(s>max) 25 max = s; 26 } 27 } 28 else 29 { 30 for(i = 1 ; i <= n ; i++) 31 for(j = i ; j <= n ; j++) 32 for(k = j ; k <= n ; k++) 33 { 34 s = i/(gcd(i,j))*j; 35 s = s/(gcd(s,k))*k; 36 if(s>max) 37 max = s; 38 } 39 } 40 printf("%I64d\n",max); 41 return 0; 42 }