negative value random in c++ [duplicate]

This question already has an answer here:

• Generate random numbers uniformly over an entire range 15 answers
• Generate random numbers using C++11 random library 4 answers

Could you help me? I need for my matrix multiplication code random values between -10 and 10. How can I do it? Here is my code

#include <iostream>
#include <stdlib.h>
#include <time.h>

using namespace std;

#define CAPACITY 30

struct Matrix
{
    int row, col;
    int** matrix;
    Matrix() {//Creates complete randomized matrix
        row = rand() % 10 + 1;
        col = rand() % 10 + 1;
        matrix = new int*[row];
        for(int i = 0; i  < row; i++) matrix[i] = new int[col];
        for(int i = 0; i < row; i++) {
            for(int j = 0; j < col; j++) matrix[i][j] = rand()%CAPACITY +     1;
        }