hdu_6016

Classes
The school set up three elective courses, assuming that these courses are A, B, C. N classes of students enrolled in these courses.
Now the school wants to count the number of students who enrolled in at least one course in each class and records the maximum number of students.
Each class uploaded 7 data, the number of students enrolled in course A in the class, the number of students enrolled in course B, the number of students enrolled in course C, the number of students enrolled in course AB, the number of students enrolled in course BC, the number of students enrolled in course AC, the number of students enrolled in course ABC. The school can calculate the number of students in this class based on these 7 data.
However, due to statistical errors, some data are wrong and these data should be ignored.
Smart you must know how to write a program to find the maximum number of students.
Input
The first line of the input gives the number of test cases T; T test cases follow.
Each case begins with one line with one integer N, indicates the number of class.
Then N lines follow, each line contains 7 data: a, b, c, d, e, f, g, indicates the number of students enrolled in A, B, C, AB, BC, AC, ABC in this class.
It’s guaranteed that at least one data is right in each test case.

Limits
T≤100
1≤N≤100
0≤a,b,c,d,e,f,g≤100
Output
For each test case output one line contains one integer denotes the max number of students who enrolled in at least one course among N classes.
Sample Input
2
2
4 5 4 4 3 2 2
5 3 1 2 0 0 0
2
0 4 10 2 3 4 9
6 12 6 3 5 3 2
Sample Output
7
15
Source
2017 Multi-University Training Contest - Team 6

小学数学,离散学的感觉自己用的太死,就直接套公式,果断wa
题意 :有三门课程abc 给你分别选a,b,c,ab,bc,ac,abc的人数求多个案例中最大的总人数;

分别求出只选a,b,c,ab,bc,ac,abc,小于0就是不合法

#include<cstdio>#include<iostream>#include<string>#include<algorithm>#include<map>using namespace std;int main(){    int t,n,i,j;  cin>>t;    {        int mm;        while(t--)        {            cin>>n;            mm=-99;            while(n--)            {                int a,b,c,ab,bc,ac,abc,ans=0;                scanf("%d%d%d%d%d%d%d",&a,&b,&c,&ab,&bc,&ac,&abc);                a=a-ac-ab+abc;                if(a<0) continue;                else                    ans+=a;                b=b-ab-bc+abc;                if(b<0) continue;                else                    ans+=b;                c=c-ac-bc+abc;                if(c<0) continue;                else                    ans+=c;                ab-=abc;                if(ab<0) continue;                else                    ans+=ab;                bc-=abc;                if(bc<0) continue;                else                    ans+=bc;                ac-=abc;                if(ac<0) continue;                else                    ans+=ac;                ans+=abc;               // cout<<ans<<endl;                mm=max(mm,ans);            }            cout<<mm<<endl;        }    }    return 0;}