int ndata,sum;
int data[100];
void solve(int s, int sign, int n);
void main(){
int i, number;
scanf(“%d%d”,&number ,&ndata);
sum = 0;
for(i = 0; i< ndata; i++)
scanf(“%d”,&data[i]);
solve(1, 1, 1);
printf(“%d”,sum);
}

void solve(int s, int sign, int n){
int i;
for(i=s; i<=ndata; i++){
sum += sign * (number /(n * data[i-1]));
solve(i + 1, -sign, n * data[i-1]);
}
}



主要是不理解solve(i + 1, -sign, n * data[i-1]);