如何优化

#include<bits/stdc++.h>
using namespace std;
int n;//循环次数 
struct student{
	char name[20];//学生名字 
	int score; //成绩 
}a[100000];//学生与成绩 
int way;//指令的种类
char name1[20]; //指令的指定
int num;//学生数 
int is2;
int main(){
	cin>>n;
	for(int ok=1;ok<=n;ok++){
		cin>>way;
		if(way==4){//4
			cout<<num;
		}else if(way==1){//1
		    cin>>name1;
			if(num!=0){
			    is2=0; 
		        for(int i=1;i<=num;i++){   
				    int is1=1;
				    for(int g=1;g<=20;g++){
					    if(a[i-1].name[g-1]!=name1[g-1])is1=0;
				    }
				    if(is1==1){
					    cin>>a[i-1].score;
					    is2=1;
					    cout<<"OK";
				    }   
			    }   
			}
			if(is2==0){
				num++;
				cin>>a[num-1].score;
				for(int i=1;i<=20;i++)a[num-1].name[i-1]=name1[i-1];
				cout<<"OK";
			} 
		}else if(way==2){//2
			cin>>name1;
			if(num==0){
				cout<<"Not found";
			}else{
				is2=0;
				for(int i=1;i<=num;i++){   
				    int is3=1;
				    for(int g=1;g<=20;g++){
					    if(a[i-1].name[g-1]!=name1[g-1])is3=0;
				    }
				    if(is3==1){
					    is2=1;
					    cout<<a[i-1].score;
				    }   
			    }
			    if(is2==0){
			    	cout<<"Not found";
				}
			}
		}else if(way==3){//3
			cin>>name1;
			if(num==0){
				cout<<"Not found";
			}else{
				is2=0;
				for(int i=1;i<=num;i++){   
				    int is4=1;
				    for(int g=1;g<=20;g++){
					    if(a[i-1].name[g-1]!=name1[g-1])is4=0;
				    }
				    if(is4==1){
					    is2=1;
					    a[i-1].name[0]='c';
					    a[i-1].name[1]='c';
					    a[i-1].name[0]='f';
					    swap(a[i-1],a[num-1]);
					    num--;
					    cout<<"Deleted successfully";
				    }   
			    }
			    if(is2==0){
			    	cout<<"Not found";
				} 
			}
		}
		if(ok!=n)cout<<endl;
	} 
    return 0;
}