Please answer in C++. This is the teachers code to modify.

#include #include #include #include #include #include using namespace std; // Class for finding execution time. // Usage: // Timer t; // Create a Timer object // some_stuff(); // Your code // double elapsed_time = t.seconds(); // Get executation time class Timer { private: clock_t clock_start; public: Timer() { reset(); } void reset() { clock_start = clock(); } double seconds() { return (double(clock()) - double(clock_start)) / CLOCKS_PER_SEC; } }; unsigned int randInt(); unsigned int randInt(unsigned int max); unsigned int randInt(unsigned int min, unsigned int max); void algorithm1(vector& v); void algorithm2(vector& v); void algorithm3(vector& v); bool verify_values(const vector& v); int main(int argc, char* argv[]) { // Set precision for timer output. cout  1) algo = atoi(argv[1]); else { cout > algo; } // Get size of vector from command line if provided, else prompt for it size_t size = 0; if (argc > 2) size = size_t(atoi(argv[2])); if (!size) { cout > size; } // Create vector of the given size vector v(size); // Fill vector with a random permutation of values from 1 through size Timer t; switch (algo) { case 1: algorithm1(v); break; case 2: algorithm2(v); break; case 3: algorithm3(v); break; default: cout  
 
  2.8 Suppose you need to generate a random permutation of the first N integers. For example, {4, 3, 1, 5, 2} and {3, 1, 4, 2, 5} are legal permutations, but {5, 4, 1, 2, 1} is not, because one number (1) is duplicated and another (3) is missing. This routine is often used in simulation of algorithms. We assume the existence of a random number generator, r, with method randInt(i,j), that generates integers between i and j with equal probability. Here are three algorithms: 1. Fill the array a from a[0] to a[N-1] as follows: To fill a[i], generate random numbers until you get one that is not already in a[0], a[1], ..., a[i-1]. 2. Same as algorithm (1), but keep an extra array called the used array. When a random number, ran, is first put in the array a, set used[ran) - true. This means that when filling a[i] with a random number, you can test in one step to see whether the random number has been used, instead of the (possibly) i steps in the first algorithm. 3. Fill the array such that a[i] - i+1. Then for(i = 1; i <>