The basic idea of the greedy algorithm is to gradually approach the given goal from an initial solution of the problem, so as to obtain a better solution as much as possible. get an approximate solution.
- there is no guarantee that the final interpretation is optimal;
- problems that cannot be used to find maximum or minimum solutions;
-Only the range of feasible solutions that satisfy certain constraints can be obtained.
Example: changing change
Java code description
public class Test {
static int MAXN = 9;
static int[] parvalue = {10000,5000,1000,500,200,100,50,20,10};
static int[] num = new int[9];
public static void main(String[] args) {
int i;
float m;
System.out.println("Please enter the amount to be processed");
Scanner sc = new Scanner(System.in);
m = sc.nextFloat();
exchange((int)(100*m));
System.out.println("Change group is");
for(i=0;i<MAXN;i++){
if(num[i]>0){
System.out.println((float)(parvalue[i]/100.0)+"元 "+num[i]+"张");
}
}
}
public static void exchange(int n){
int i;
for(i = 0;i<MAXN;i++){
if(n>parvalue[i]){ //find the maximum denomination
break;
}
}
while(n>0&&i<MAXN){ //Loop to find progressively smaller denominations
if(n>=parvalue[i]){
n-=parvalue[i]; //Get the one with the largest denomination
num[i]++; //Add one to the current denomination counter
}else if(n<10&&n>=5){
num[MAXN-1]++;
break;
}else{
i++;
}
}
}
}
operation result:
