Academy Online tsinghuax:00740043_2x C + + Language programming advanced Sixth Chapter Lab

The first question: The maximum number of sub-arrays and

Title Description

Given an array a[0,..., n-1], find its maximum subarray (length >=1) and

Enter a description

First line an integer n (1<=n<=5000), and then enter n integers (each integer range [-5000, 5000])

Output description

Outputs an integer representing the maximum number of sub-arrays and

Sample input

51-1 1 1-1

Sample output

2

#include <stdio.h>intMaxsum (int*a,intN) {    intmax=-1; inti,j,sum;  for(i=0; i<n;i++) {sum=0;  for(j=i;j<n;j++) {sum+=A[j]; if(sum>max) Max=sum; }    }    returnMax;}intMainintargcConst Char*argv[]) {    intLen; scanf ("%d",&Len); intI,a[len];  for(i=0; i<len;i++) scanf ("%d",&A[i]); printf ("%d", Maxsum (A,len)); return 0;}

Second question: The number of palindrome sequences of a string

Title Description

The number of palindrome sub-sequences (subsequence length >=1) for a string of not more than 15 length.

Enter a description

Enter a string that is not more than 15 in length, and the string is represented by a lowercase letter

Output description

Output the number of palindrome subsequence

Sample input

Abaa

Sample output

10

Comments

In this case, all of its palindrome subsequence are:
A,b,a,a,aba,aba,aa,aa,aa,aaa
A subsequence of a string is a new string that is stripped of some characters on the original string but does not break the relative position (in front or behind) of the remaining elements.

#include <string>#include<iostream>using namespacestd;stringSTR, creat="";intans=0;BOOLused[ -]={false};BOOLBack_forward (stringstr) {     for(intI=0; I<str.length ()/2; i++)    {        if(Str[i]!=str[str.length ()-i-1])            return false; }    return true;}voidSearchintLenintstart) {    if(len<=0)    {        if(Back_forward (creat)) ans++; return; }     for(inti = Start;i<str.length (); i++)    {        if(!Used[i]) {Used[i]=true; Creat.append (Str,i,1); Search (len-1, i+1); Used[i]=false; Creat.erase (Creat.length ()-1,1); }    }}intMainintargcConst Char*argv[]) {cin>>str;  for(intI=1; I<=str.length (); i++) Search (i,0); cout<<ans; return 0;}

Question three: array k decimal

Title Description

Given an array of integers a[0,..., n-1], find the K decimal in the array

Enter a description

First enter the array length n and K, where 1<=n<=5000, 1<=k<=n

Then output n shaping elements, the range of each number [1, 5000]

Output description

K Decimal in the array

Sample input

4 21 2) 3 4

Sample output

2

#include <vector>#include<algorithm>#include<iostream>using namespacestd;intMainintargcConst Char*argv[]) {    intn,k; CIN>>n>>K; Vector<int>a (N,0);  for(intI=0; i<n;i++) {cin>>A[i];    } sort (A.begin (), A.end ()); cout<<a[k-1]; return 0;}

Additional questions: Maximum sub-array and (enhanced version)

Title Description

Given an array a[0,..., n-1], find its maximum subarray (length >=1) and

Enter a description

First line an integer n (1<=n<=100000), and then enter n integers (each integer range [-5000, 5000])

Output description

Outputs an integer representing the maximum number of sub-arrays and

Sample input

51-1 1 1-1

Sample output

2

Comments

The subject and lab 6-1 are larger than the length of the array, and the efficiency of the program is more demanding.

#include <stdio.h>intMaxintXinty) {    return(x>y)?x:y;}intMaxsum (int*a,intN) {    inti; intNall,nstart; Nall=a[n-1]; Nstart=a[n-1];  for(i=n-2; i>=0; i--) {Nstart=max (a[i],a[i]+Nstart); Nall=Max (Nall,nstart); }    returnNall;}intMainintargcConst Char*argv[]) {    intLen; scanf ("%d",&Len); intI,a[len];  for(i=0; i<len;i++) scanf ("%d",&A[i]); printf ("%d", Maxsum (A,len)); return 0;}

Academy Online tsinghuax:00740043_2x C + + language programming advanced Sixth Lab