how to march two rows of data and return only 1 value?

[cxinio]

I've got two columns of data.

int a[6]={1,3,5,8,10,12};
int b[3]={3,5,9};
int c[6]={0};

if a is equal to ANY of the data in b, then c= a*2
if a isn't equal to any of the data in b, then c=a.
Here is the answer I want

c[6]={1,6,10,8,10,12}

If I use two for loop, I get 18 values at last.....I don't know how to do it.

int a[6]={1,3,5,8,10,12};
int b[3]={3,5,9};
int c[6]={0};

for(int i=0;i<6;++i){
for(int j=0;j<3;++j){
if(a[i]==b[j]){
c[i]=a[i]*2;

}
else{
c[i]=a[i];
}
}
}

[coder777]

what makes you think that you get 18 values?

[cxinio]

origianlly, I thought because of the two for loop,
for(int i=0;i<6;++i){
for(int j=0;j<3;++j){

6*3=18, so finally there should be 18 values, though I defined c[6]

But I tried, I am wrong. Anyway, I have no idea how to write this.

[coder777]

No, since you use i and j correctly for indexing. The index never exceed 6 or 3 respectively.

what you need is break; after c[i]=a[i]*2; otherwise you may store the wrong values

[cxinio]

perfect, thanks a lot.