如何搜索数组中的元素并将其打印出整行？我一直在做这样的解决方法，但似乎无法输出我的预期。
#include <iostream>
#include <stdlib.h>
#include <string>
#include <ctype.h>
#include <sstream>
using namespace std;
int main() {
string items[9][3] = {{"A","BALOT","25.00"},
{"B","CANTON","20.00"},
{"C","NIDO","100.00"},
{"D","KETCHUP","50.00"},
{"E","MAGGI","15.00"},
{"F","ALASKA","60.00"},
{"G","VINEGAR","25.00"},
{"H","OIL","70.00"},
{"I","COKE","10.00"}};
// PARA SA MAPRINT YUNG ARRAY.
cout << "MANG JUAN'S 10-DAHAN\n\n";
for (int i = 0; i < 9; i++) {
for (int j = 0; j < 3; j++)
cout << items[i][j] << ( (j < 2) ? "-" : "\t" );
if (i < 6) {
cout << "\t";
i += 2;
}
else if (i != 8) {
cout << "\n";
i -= 6;
}
} // END OF ARRAY PRINTING
char choice;
int ctr = 1, quantity;
string purchased;
cout << "\n\nWOULD YOU LIKE TO PURCHASE? Y/N\n\n";
cin >> choice;
if(choice == 'n' || choice == 'N') {
cout << "Thank you. ";
}
else if(choice == 'y' || choice == 'Y') {
string numPref;
while (true) {
if(ctr > 11) {
cout << "\n\nTHE SYSTEM EXCEEDED ITS LIMIT\n\n";
break;
} else {
if(ctr == 1) numPref = "st";
else if(ctr == 2) numPref = "nd";
else if(ctr == 3) numPref = "rd";
else if(ctr > 3) numPref = "th";
}
cout << "\n\nPLEASE ENTER " << ctr << numPref << " ITEM:\t";
cin >> purchased;
if(!cin) {
cout << "Letters only";
break;
} else {
if(true) {
cout << "HOW MANY? ";
cin >> quantity;
if(!cin) {
cout << "Enter number only. ";
break;
} else {
cout << "PRICE PER ITEM: ";
///////// Look for the element and print the entire row /////////////
string matchedRow[3];
for (int i = 0; i < 3; i++) {
string oneRow[] = items[i];
if (oneRow[0] == purchased) {
matchedRow = oneRow;
break;
}
}
for (int i = 0; i < matchedRow.length; i++) {
cout << matchedRow[i] + "\t\t";
}
////////////////////////////////////////////
}
ctr++;
} // end of else - if (!cin) for quantity input check
} // end of char check
} // End of else for (!cin)
} // End of while loop for numPref
} // End of else if (choice)
system("PAUSE");
return 0;
}
实施例：
如果用户在A上输入Please enter item，程序将输出Price per item以及阵列上的相应价格。
Sample Run:
lease enter item: A // user input
How many? 3 // user input
Price per item: 25.00 // not user input
答案 0 :(得分：1)
#include <algorithm>
#include <iostream>
int main() {
// Keep it sorted!
std::string items[9][3] = {
{"A","BALOT","25.00"},
{"B","CANTON","20.00"},
{"C","NIDO","100.00"},
{"D","KETCHUP","50.00"},
{"E","MAGGI","15.00"},
{"F","ALASKA","60.00"},
{"G","VINEGAR","25.00"},
{"H","OIL","70.00"},
{"I","COKE","10.00"}};
typedef std::string Item[3];
Item* last_item = items + sizeof(items) / sizeof(Item);
struct Less {
bool operator () (const Item& a, const std::string& b) const {
return a[0] < b;
}
};
std::string in;
std::cin >> in;
Less less_item;
Item* item = std::lower_bound(items, last_item, in, less_item);
if(item == last_item || (*item)[0] != in) std::cout << "Not found" << std::endl;
else std::cout << "Found: " << (*item)[0] << ": " << (*item)[1] << ", Price = " << (*item)[2] << std::endl;
return 0;
}
答案 1 :(得分：1)
使用指针复制行：
string *oneRow = items[i];
然后您可以访问价格：
oneRow[2]
修改后的程序：
#include <iostream>
#include <stdlib.h>
#include <string>
#include <ctype.h>
#include <sstream>
using namespace std;
int main() {
string items[9][3] = {{"A","BALOT","25.00"},
{"B","CANTON","20.00"},
{"C","NIDO","100.00"},
{"D","KETCHUP","50.00"},
{"E","MAGGI","15.00"},
{"F","ALASKA","60.00"},
{"G","VINEGAR","25.00"},
{"H","OIL","70.00"},
{"I","COKE","10.00"}};
// PARA SA MAPRINT YUNG ARRAY.
cout << "MANG JUAN'S 10-DAHAN\n\n";
for (int i = 0; i < 9; i++) {
for (int j = 0; j < 3; j++)
cout << items[i][j] << ( (j < 2) ? "-" : "\t" );
if (i < 6) {
cout << "\t";
i += 2;
}
else if (i != 8) {
cout << "\n";
i -= 6;
}
} // END OF ARRAY PRINTING
char choice;
int ctr = 1, quantity;
string purchased;
cout << "\n\nWOULD YOU LIKE TO PURCHASE? Y/N\n\n";
cin >> choice;
if(choice == 'n' || choice == 'N') {
cout << "Thank you. ";
}
else if(choice == 'y' || choice == 'Y') {
string numPref;
while (true) {
if(ctr > 11) {
cout << "\n\nTHE SYSTEM EXCEEDED ITS LIMIT\n\n";
break;
} else {
if(ctr == 1) numPref = "st";
else if(ctr == 2) numPref = "nd";
else if(ctr == 3) numPref = "rd";
else if(ctr > 3) numPref = "th";
}
cout << "\n\nPLEASE ENTER " << ctr << numPref << " ITEM:\t";
cin >> purchased;
if(!cin) {
cout << "Letters only";
break;
} else {
if(true) {
cout << "HOW MANY? ";
cin >> quantity;
if(!cin) {
cout << "Enter number only. ";
break;
} else {
cout << "PRICE PER ITEM: ";
///////// Look for the element and print the entire row /////////////
string *matchedRow;
const int length = 3;
for (int i = 0; i < 3; i++) {
string *oneRow = items[i];
if (oneRow[0] == purchased) {
matchedRow = oneRow;
cout << matchedRow[2];
break;
}
}
//you don't need this
/*
for (int i = 0; i < length; i++) {
cout << matchedRow[i] + "\t\t";
}
*/
////////////////////////////////////////////
}
ctr++;
} // end of else - if (!cin) for quantity input check
} // end of char check
//} // End of else for (!cin) //spare bracket
} // End of while loop for numPref
} // End of else if (choice)
//system("PAUSE");
//return 0;
}
答案 2 :(得分：0)
在您定义字符串oneRow []的行中，我认为它应该是
string oneRow[3] = {"Z","WATER","00.00"}; // default initialization
oneRow[0] = items[i][0];
oneRow[1] = items[i][1];
oneRow[2] = items[i][2];