bzoj 2529: [Poi2011]Sticks

Description

Little Johnny was given a birthday present by his grandparents. This present is a box of sticks of various lengths and colours. Johnny wonders if there are three sticks in the set he has been given that would form a triangle with different-coloured sides. Let us note that Johnny is interested in non-degenerate triangles only, i.e., those with positive area.
给出若干木棍，每根木棍有特定的颜色和长度。问能否找到三条颜色不同的木棍构成一个三角形。
(注意这里所说的三角形面积要严格大于0)

第一行给出一个整数k(3<=k<=50),表示颜色的种数。这k种颜色被标号为1至k。
接下来k行，第i+1描述颜色为i的木棍的信息。
首先一个整数Ni(1<=Ni<=10^6)表示颜色为i的木棍的数量。
接下来Ni个整数，表示这Ni根木棍各自的长度。
所有木棍的长度<=10^9。总木棍数量<=10^6。

你的程序应该仅输出一行
如果有解，输出6个整数，分别表示第一条边的颜色，第一条边的长度，第二条边的颜色，第二条边的长度，第三条边的颜色，第三条边的长度，这六个整数以空格分割。
如果有多组解，随便输出一组即可。
如果无解，输出 NIE

Input

In the first line of the standard input an integer k(3<=k<=50)is given, which is the number of different colours of sticks. The colours themselves are numbered from 1 to k.
The following klines contain descriptions of the sticks of particular colours. The line no. i+1holds integers that describe the sticks of colour , separated by single spaces. The first of these numbers, Ni(1<=Ni<=10^6) denotes the number of sticks of colour . It is followed, in the same line, by Niintegers denoting the lengths of the sticks of colour . All lengths are positive and do not exceed10^9. Furthermore, the total number of all sticks does not exceed 10^6.0020
In tests worth at least 30% of the points the following holds in addition: the total number of the sticks does not exceed 250.

Output

Your program should print (on the first and only line of the standard output) either:
· six integers, separated by single spaces, that describe the construction of a triangle with different-coloured sides as follows: the colour and the length of the first stick, the colour and the length of the second stick, and the colour and the length of the third stick,
· or the word NIE (Polish for no) if no such triple of sticks exists.
If there are multiple triples of different-coloured sticks that give rise to a triangle, your program may pick one such triple arbitrarily.

Sample Input

41 422 6 93 8 4 81 12

Sample Output

3 8 4 12 2 9

HINT

Source

鸣谢Kac

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solution

• 用堆维护前三长的颜色不同的木棒，看他们能不能组成三角形

code

#include<cstdio>#include<cstring>#include<algorithm>using namespace std;typedef long long ll;template<typename T>void input(T &x) {    x=0; T a=1;    register char c=getchar();    for(;c<'0'||c>'9';c=getchar())        if(c=='-') a=-1;    for(;c>='0'&&c<='9';c=getchar())        x=x*10+c-'0';    x*=a;    return;}#define MAXN 1000010struct Stick {    int col,len;    Stick(int col=0,int len=0):        col(col),len(len) {}    void Print() {        printf("%d %d ",col,len);        return;    }    bool operator < (const Stick &q)const {        return len<q.len;    }    Stick operator + (const Stick &q) const {        Stick s=*this;        s.len+=q.len;        return s;    }};Stick a[MAXN],ans[4];int main() {    int k;    input(k);    int cnt=0;    for(int i=1,Ni;i<=k;i++) {        input(Ni);        for(int j=1,len;j<=Ni;j++) {            input(len);            a[++cnt]=Stick(i,len);        }    }    sort(a+1,a+cnt+1);    bool flag;    for(int i=1;i<=cnt;i++) {        flag=false;        for(int j=1;j<=3;j++)            if(ans[j].col==a[i].col) {                ans[j].len=a[i].len;                flag=true;            }        if(!flag) ans[1]=a[i];        sort(ans+1,ans+4);        if(ans[3]<ans[1]+ans[2]&&ans[1].len) {            for(int j=1;j<=3;j++)                ans[j].Print();            return 0;        }    }    printf("NIE\n");    return 0;}