Check the questions hdu3038 how many answers are wrong

How Many Answers Are Wrong

Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others)
Total Submission (s): 521 Accepted Submission (s): 213

Problem DescriptionTT and FF are... friends. Uh... very good friends-________-B

FF is a bad boy, he is always wooing TT to play the following game with him. this is a very humdrum game. to begin with, TT shocould write down a sequence of integers -_-!! (Bored ).

Then, FF can choose a continuous subsequence from it (for example the subsequence from the third to the nth integer within sively ). after that, FF will ask TT what the sum of the subsequence he chose is. the next, TT will answer FF's question. then, FF can redo this process. in the end, FF must work out the entire sequence of integers.

Boring ~~ Boring ~~ A very boring game !!! TT doesn' t want to play with FF at all. To punish FF, she often tells FF the wrong answers on purpose.

The bad boy is not a fool man. FF detects some answers are incompatible. Of course, these contradictions make it difficult to calculate the sequence.

However, TT is a nice and lovely girl. she doesn' t have the heart to be hard on FF. to save time, she guarantees that the answers are all right if there is no logical mistakes indeed.

What's more, if FF finds an answer to be wrong, he will ignore it when judging next answers.

But there will be so empty questions that poor FF can't make sure whether the current answer is right or wrong in a moment. so he decides to write a program to help him with this matter. the program will receive a series of questions from FF together with the answers FF has received ed from TT. the aim of this program is to find how many answers are wrong. only by ignoring the wrong answers can FF work Out the entire sequence of integers. Poor FF has no time to do this job. And now he is asking for your help ~ (Why asking trouble for himself ~~ Bad boy)

 

 

InputLine 1: Two integers, N and M (1 <= N <= 200000, 1 <= M <= 40000). Means TT wrote N integers and FF asked her M questions.

Line 2 .. M + 1: Line I + 1 contains three integer: Ai, Bi and Si. means TT answered FF that the sum from Ai to Bi is Si. it's guaranteed that 0 <Ai <= Bi <= N.

You can assume that any sum of subsequence is fit in 32-bit integer.

 

 

OutputA single line with a integer denotes how many answers are wrong.

 

Sample Input10 5 1 10 100 7 10 28 1 3 32 4 6 41 6 6 1

 

Sample Output1 has something to say: in fact, the essence of the query set lies in the relationship between the parent node and the child node. After figuring out the relationship between the parent node and the child node, it is very easy to compress the path ~ For example, sum [I] indicates the difference between I and the parent node. From the parent node to the root node, the link is updated layer by layer when the path is compressed. View Code

#include<stdio.h>
#include<string.h>
#define MAX 200005
int f[MAX],sum[MAX];
int n,m;
void init()
{
    memset(sum,0,sizeof(int)*(n+2));
for(int i=0;i<=n;i++) f[i]=i;
}
int find(int x)
{
if(f[x]==x) return x;
int tx=find(f[x]);
    sum[x]+=sum[f[x]];
    f[x]=tx;
return tx;
}
void unio(int x,int y,int tx,int ty,int w)
{
    f[ty]=tx;
    sum[ty]=sum[x]-sum[y]+w;
}
int main()
{
int ans=0,x,y,w,tx,ty;
while(scanf("%d%d",&n,&m)!=EOF)
    {
        init();ans=0;
for(int i=1;i<=m;i++)
        {
            scanf("%d%d%d",&x,&y,&w);
            x--;
            tx=find(x);ty=find(y);
if(tx==ty&&sum[y]-sum[x]!=w) ans++;
elseif(tx!=ty) unio(x,y,tx,ty,w);
        }
        printf("%d\n",ans);
    }
return0;
}