C + + pointer exercise

1#include <iostream>2 3 using namespacestd;4 5 //to change the value of a variable in the keynote function through a function call:6 //(1) in the keynote function, the address of the variable or the pointer to the variable as an argument7 //(2) in the modulated function, accept the address of the variable with the pointer type parameter8 //(3) in the modulated function, change the value of the parameter pointed to the variable9 voidSWAP2 (int* x,int*y) {Ten     intT; Onet = *x; A*x = *y; -*y =T; - } the  - //find the maximum number in an array - //first declare a pointer variable and let him point to the address of the first element of the array - //use a For loop to compare the number pointed to by the pointer to each number in the array + //let the pointer point to the maximum number of comparisons after each comparison - //Finally, the pointer to the largest tree in the array is returned . + int* SWAP1 (intAintLen) { A     int* t =A; at      for(inti =1; i < Len;i + +){ -         if(*t<* (A +i)) { -t = a +i; -         } -     } -     returnT; in } -  to //Use the addition operation of the pointer to add all the elements in an array and return the result + //declares a pointer variable and points it to the first element address of array a - //Use the pointer to iterate through all the elements in the array, add to the variable sum, and return the value of the last int type the intSWAP3 (intBintLen) { *     int* p =A; $     intsum =0;Panax Notoginseng      for(inti =0;i<5; i++){ -         //The pointer 's addition operation, the pointer variable is 1 each time, the pointer moves backwards the number of bytes that the pointer type occupies the         //that is, when the pointer variable is 1 each time, the pointer points to the next element of the array +Sum + = *p + +; A     } the     returnsum; + } -  $ //to sort the elements of an array using the Bubbling method $ voidSWAP4 (int* Array,intLen) { -     inttemp =0; -      for(inti =1; i < Len;i + +){ the          for(intj =0; J<len-i;j + +){ -             if(array[j]>array[j+1]){Wuyitemp =Array[j]; theARRAY[J] = array[j+1]; -array[j+1] =temp; Wu             } -         } About     } $ } -  - voidMain () { -     //computes the sum of an array A     intA[] = {1,2,3,4,5}; +     intAsize =sizeof(a)/sizeof(int); the     intsum =swap3 (a,asize); -cout <<"the sum of all elements of array A is:"<< sum <<Endl; $  the     //calculates the maximum number in an array the     intB[] = {2,5, the, -,4,7}; the     intBsize =sizeof(b)/sizeof(int); the     int* t =Swap1 (b,bsize); -cout <<"The maximum number of all elements of array A is:"<< *t <<Endl; in  the     //Exchange values for two variables the     intx =1, y =2; About     int*pa = &x, *PB = &y; thecout <<"x="<<x<<"; y="<<y<<Endl; the swap2 (PA,PB); thecout <<"After calling Swap2:"<<"\ n"<<"x="<<x<<"; y="<<y<<Endl; +  -     //Array Sorting the     intarray[5];Bayicout <<"Please enter a 5 integer"<<Endl; the      for(inti =0;i<5; i++){ theCIN >>Array[i]; -     } -cout <<"before sorting:"; the      for(inti =0; I <5; i + +){ thecout << Array[i] <<"\ t" ; the     } theSWAP4 (Array,5); -cout <<"\ n after sorting:"; the      for(inti =0; I <5; i + +){ thecout << Array[i] <<"\ t" ; the     }94}

C + + pointer exercise