思维

codeforces 714 A

Today an outstanding event is going to happen in the forest — hedgehog Filya will come to his old fried Sonya!

Sonya is an owl and she sleeps during the day and stay awake from minute l₁ to minute r₁ inclusive. Also, during the minute k she prinks and is unavailable for Filya.

Filya works a lot and he plans to visit Sonya from minute l₂ to minute r₂ inclusive.

Calculate the number of minutes they will be able to spend together.

The only line of the input contains integers l₁, r₁, l₂, r₂ and k (1 ≤ l₁, r₁, l₂, r₂, k ≤ 10¹⁸, l₁ ≤ r₁, l₂ ≤ r₂), providing the segments of time for Sonya and Filya and the moment of time when Sonya prinks.

Input

1 10 9 20 1

Output

2

Input

1 100 50 200 75

Output

50

题意：给你两个段  1--10   9--20。  求重合的多少，并且如果e在重合的范围内，就再去一。
重合的段，即左端取大的，右边取小的。

#include <iostream>
#include<algorithm>
#include<cstdio>
typedef long long ll;
using namespace std;
int main()
{
    ll a,b,c,d,e,ans;
    scanf("%lld %lld %lld %lld %lld",&a,&b,&c,&d,&e);
    ll a1=max(a,c);
    ll b1=min(b,d);
    if(b1>=a1)
    {
        ans=b1-a1+1;
        if(a1<=e&&e<=b1)
            ans-=1; 
        printf("%lld\n",ans);
    }
    else
        printf("0\n");

    



    return 0;
}

 

 

codeforces 719 b

题意：给你一个只有r 和b构成的串，问最少改变几次能使串变成rbrbrbr  或者brbrbr

1：单纯改变这个字符，例如：把b改成r;

2：交换任意位置的 r和b;

Input

5
rbbrr

Output

1

Input

5
bbbbb

Output

2

Input

3
rbr

Output

0

#include <iostream>
#include<cstdio>
#include<algorithm>
using namespace std;
typedef long long ll;
int main()
{
    char a[100010];
    ll n,i,r1=0,b1=0,r2=0,b2=0;
    scanf("%lld",&n);
    scanf("%s",a);
    for(i=0;i<=n-1;i++)
    {
        if(a[i]=='r'&&i%2!=0)
        r1++;
        if(a[i]=='b'&&i%2==0)
            b2++;
        if(a[i]=='r'&&i%2==0)
            r2++;
        if(a[i]=='b'&&i%2!=0)
            b1++;
    }
    printf("%lld\n",min(max(r1,b2),max(r2,b1)));
    return 0;
}