Resposta :
#include <stdio.h>
#include <time.h>
#include <stdlib.h>
void funcao (int x, int y){
srand(time(NULL));
int vetor[x], indice;
int size_t = sizeof(vetor)/sizeof(vetor[0]);
for (int a=0;a<size_t;a++){
vetor[a]=rand()%10+1;
printf("[%d]::%d\t",a, vetor[a]);
}
for (int i=0;i<size_t;i++){
if(vetor[i]==y) {indice=i; break;}
else indice=-1;
}
if (indice!=-1)printf("\nPosicao> %d\n",indice);
else printf("\n%d", indice);
}
int main() {
int param_1, param_2;
printf("Tamanho do Vetor: ");scanf("%d",¶m_1);
printf("Valor a ser encontrado: ");scanf("%d",¶m_2);
funcao(param_1,param_2);
return 0;
}