Project Duration(CPU Scheduling)

#include<iostream> 
#include<bits/stdc++.h>
using namespace std; 
int mat[10][6]; 
int avgt=0,avgw=0;
void swap(int *a,int *b) 
{ 
	int temp = *a; 
	*a = *b; 
	*b = temp; 
} 
void arrangeArrival(int num, int mat[][6]) 
{ 
	for(int i=0;i<num;i++) 
	{ 
		for(int j=0;j<num-i-1;j++) 
		{ 
			if(mat[j][1]>mat[j+1][1]) 
			{ 
				for(int k=0;k<5;k++) 
				{ 
					swap(mat[j][k],mat[j+1][k]); 
				} 
			} 
		} 
	} 
} 
void completionTime(int num, int mat[][6]) 
{ 
	int temp, val; 
	mat[0][3]=mat[0][1]+mat[0][2]; 
	mat[0][5]=mat[0][3]-mat[0][1]; 
	mat[0][4]=mat[0][5]-mat[0][2]; 
	for(int i=1;i<num;i++) 
	{ 
		temp=mat[i-1][3]; 
		int low=mat[i][2]; 
		for(int j=i;j<num;j++) 
		{ 
			if(temp>=mat[j][1]&&low>=mat[j][2]) 
			{ 
				low=mat[j][2]; 
				val=j; 
			} 
		} 
		mat[val][3]=temp+mat[val][2]; 
		mat[val][5]=mat[val][3]-mat[val][1]; 
		mat[val][4]=mat[val][5]-mat[val][2]; 
		for(int k=0;k<6;k++) 
		{ 
			swap(mat[val][k],mat[i][k]); 
		} 
	} 
} 
int main() 
{ 
	int num, temp; 
	cin>>num; 
	for(int i=0;i<num;i++) 
	{ 
		cin>>mat[i][2]; 
      	mat[i][0]=i+1; 
		cin>>mat[i][1]; 
	} 
	arrangeArrival(num,mat); 
	completionTime(num,mat); 
	cout<<"Pid BT AT WT TAT\n"; 
	for(int i=0;i<num;i++) 
	{ 
		if(i==0){
      		cout<<"p["<<mat[i][0]<<"] "<<mat[i][2]<<" "<<mat[i][1]<<" 0 "<<mat[i][5]-1<<"\n"; 
 			avgt+=mat[i][5]-1;
        }
      	else{
          	cout<<"p["<<mat[i][0]<<"] "<<mat[i][2]<<" "<<mat[i][1]<<" "<<mat[i][4]-1<<" "<<mat[i][5]-1<<"\n";
        	avgw+=mat[i][4]-1;
          	avgt+=mat[i][5]-1;
        }
    } 
  	cout<<"AVERAGE WAITING TIME:"<<fixed<<setprecision(6)<<(float)avgw/(float)num<<endl;
  	cout<<"AVERAGE TURN AROUND TIME:"<<fixed<<setprecision(6)<<(float)avgt/(float)num;
} 
//code by lakshay singhwal