Skills of CCF question 2

1. Then sell vegetables ： Store... In two arrays

    scanf("%d", &n);
    for(i = 1; i <= n * 2; i++) {
        scanf("%d%d", &ai, &bi);
        for(j = ai; j < bi; j++)
            cnt[j]++;
    }

2. Take a jump ： Basic points + Extra points Set two variables if（a==1）plaus=0 else  

 while(scanf("%d", &a) != EOF && a) {
        sum += a;
        if(a == 1)
            plus = 0;
        else if(a == 2) {
            sum += plus;
            plus += 2;
        }
    }

3. Colliding balls ： Outer layer t loop , Inner layer n A small ball cycle , Location pos[n] , Direction step[n] simulation

/* CCF201803-2  Colliding balls  */
 
#include <iostream>
 
using namespace std;
 
const int L = 1000;
int pos[L + 1], step[L + 1];
 
int main()
{
    int n, l, t;
 
    cin >> n >> l >> t;
    for(int i = 0; i < n; i++) {
        cin >> pos[i];
        //  Start right , Reach both ends and turn back 
        step[i] = 1;
        if(pos[i] == l || pos[i] == 0)
            step[i] = -step[i];
    }
 
    for(int i = 0; i < t; i++) {
        //  Take a step 
        for(int j = 0; j < n; j++) {
            pos[j] += step[j];
            //  Reach both ends and turn back 
            if(pos[j] == l || pos[j] == 0)
                step[j] = -step[j];
        }
 
        //  Judge whether to meet , When we meet, we turn around （ Avoid repeated comparisons ）
        for(int j = 0; j < n; j++)
            for(int k = j + 1; k < n; k++)
                if(pos[k] == pos[j])
                    step[k] = -step[k], step[j] = -step[j];
    }
 
    for(int i = 0; i < n; i++)
        cout << pos[i] << " ";
    cout << endl;
 
    return 0;
}
 

4. Minimum difference ：sort Sort

  sort(a, a + n);
 
    //  Calculate the minimum value of the difference 
    int min = N2;
    for(int i=1; i<n; i++) {
        int d = a[i] - a[i - 1];
        if(d < min)
            min = d;
    }

 5. Divide the cake , The data packet , Edge input , Side record ,count++ after sub Set as 0, Consider the last piece of cake alone

/* CCF201703-1  Divide the cake  */
 
   cin >> n >> k;
    for(int i=1; i<=n; i++) {
        cin >> val;
 
        if((sub += val) >= k) {
            count++;
            sub = 0;
        }
    }
    if(sub > 0)
        count++;
 
 

6. The students lined up ： Good at using vector Of insert and erase（ Move elements ）,STL find（） Return iterator ,distance（）

   //  Simulate the moving process 
     for(int i=1; i<=m; i++) {
        cin >> p >> q;
 		// Student number , Adjustment operation  
 	vector <int> :: iterator it =find(v.begin(),v.end(),p);
 		// Find the operation element location  
        int pos=distance(v.begin(), it) ;
        // Mobile is realized by inserting and deleting  
        v.insert(v.begin() + pos + (q > 0 ? q + 1 : q), p);
        v.erase(v.begin() + pos + (q < 0 ? 1 : 0));
    } 

7. The middle number ： Good at using lower_bound(),upper_bound()

    //  Sort 
    sort(val, val+n);
     //  Find the middle number 
    int mid = val[n / 2];
    int lb = lower_bound(val, val + n, mid) - val;
    int ub = upper_bound(val, val + n, mid) - val;
     //  Output results 
    if(n - ub == lb)
        cout << mid << endl;
    else
        cout << -1 << endl;

8. Wage calculation （ pre-tax / After tax / tax rate / Three table mapping data range conversion ）

/* CCF201612-2  Wage calculation  */
 
int salaryrange[] = {3500, 3500+1500, 3500+4500, 3500+9000, 3500+35000, 3500+55000, 3500+80000 };
int taxrate[] = {3, 10, 20, 25, 30, 35, 45};
const int SIZE = sizeof(salaryrange) / sizeof(int);
 
int range[SIZE];
 
int main()
{
    int t, s;
 
    //  Seek various income ranges 
    range[0] = salaryrange[0];
    for(int i=1; i<SIZE; i++) {
        range[i] = range[i-1] + (salaryrange[i] - salaryrange[i-1])
                - (salaryrange[i] - salaryrange[i-1]) * taxrate[i-1] / 100;
    }
  
 // Income range 
    int i;
    for(int i=0; i<SIZE; i++)
        if(t <= range[i])
            break;
 
    //  Instead, ask for pre tax salary 
    if(i == 0)
        s = t;
    else {
        s = salaryrange[i-1] + (t - range[i-1]) * 100 / (100 - taxrate[i-1]);
    }
 
// Function abstraction 
// pre-tax  （ Pay attention to the wage expression ）  tax rate   After tax   Three forms    Range judgment   Wage conversion 
int X[]={3500,3500+1500,3500+4500,3500+9000,3500+35000,3500+80000};
int K[]={3,10,20,25,30,35,45};
const int SIZE=sizeof(X)/sizeof(int);// Number of salary range grades  
int Y[SIZE];
int main(){
	// Recurrence , initialization Y form ; 
	Y[0]=X[0];
	for(int i=0;i<SIZE;i++){
		Y[i]=Y[i-1]+(X[i]-X[i-1])-(X[i]-X[i-1])* K[i-1] / 100;
	}
	// Input  
	int  x,y,i;
	scanf("%d",&y);
	// find y The scope of the  
	 for( i=0;i<SIZE;i++){
	 	if(y<=Y[i])break;
	 }
	 // Calculate original salary , Output x 
	if(i==0) x=y;
	else{
		x=X[i-1]+(y-Y[i-1])*100/(100-K[i-1]);
	}

9. The sum of numbers

    while(n) {
        sum += n % 10;
        n /= 10;
    }

// String version 
    string a;
    for(int i=0;i!=a.size();i++)
        sum+=a[i]-'0';
// A character array 
	char num[50];
	scanf("%s",num);
	for(int i=0;i<strlen(num);i++)
        sum+=num[i]-'0';