Code for finding string between "" in a data structure - c++

Question

I need help to solve the following:
Lets say I have the number 70368 in int var and that I want to find the corresponding string "EVT_ACP_CAPT_MIC_FLT" in the structure below and load it ( including the "") to a
char* event variable
The code solution must work for any number lenght between 1 to 5.
struct NameOffset TestEvents[] = {
{ "EVT_ACP_CAPT_LAST1", 70387 },
{ "EVT_ACP_CAPT_LAST1", 70387 },
{ "EVT_ACP_CAPT_LAST2", 70512 },
{ "EVT_ACP_CAPT_LAST2", 70512 },
{ "EVT_ACP_CAPT_MASK_BOOM_SWITCH", 70385 },
{ "EVT_ACP_CAPT_MIC_FLT", 70368 },
{ "EVT_ACP_CAPT_MIC_HF1", 70510 },
{ "EVT_ACP_CAPT_MIC_HF2", 70511 },
};
The table is in real very long, this is just a few lines to show the structure.

Answer 1

Assuming that the fields of struct NameOffset are Name and Offset, you can find a match using a loop, like this:
for (int i = 0 ; i != sizeof(TestEvents)/sizeof(struct NameOffset) ; i++) {
if (PmdgEvents[i].Offset == intVar) {
printf("%s\n", PmdgEvents[i].Name);
break;
}
}

Answer 2

The brute-force approach is to use a loop and compare the second struct member to identigfy the right struct.
If the code will be executed regularly, you should use a unordered_map: load the data to a unordered_map<int, string> (or char * instead of string if you like) and then use
event_map[code];
to access the string.
#include <unordered_map>
#include <iostream>
using namespace std;
struct NameOffset {
const char *event;
int code;
};
struct NameOffset TestEvents[] = {
{ "EVT_ACP_CAPT_LAST1", 70387 },
{ "EVT_ACP_CAPT_LAST2", 70512 },
{ "EVT_ACP_CAPT_MASK_BOOM_SWITCH", 70385 },
{ "EVT_ACP_CAPT_MIC_FLT", 70368 },
{ "EVT_ACP_CAPT_MIC_HF1", 70510 },
{ "EVT_ACP_CAPT_MIC_HF2", 70511 },
};
#define N_ELEMENTS (sizeof(TestEvents) / sizeof(NameOffset))
int main() {
unordered_map<int, const char *> event_map;
for (NameOffset *it = TestEvents, *it_end = TestEvents + N_ELEMENTS;
it != it_end; ++it) {
event_map[it->code] = it->event;
}
cout << event_map[70387] << endl;
cout << event_map[70512] << endl;
cout << event_map[70385] << endl;
cout << event_map[70368] << endl;
cout << event_map[70510] << endl;
cout << event_map[70511] << endl;
return 0;
}

Answer 3

Create a Map of <int,string> and then index the map with the corresponding value you want to search
#include<iostream>
#include<map>
#include<string>
using namespace std;
int main (){
std::pair<int,string> TestEvents[] = {
make_pair( 70387,"EVT_ACP_CAPT_LAST1" ),
make_pair( 70???,"EVT_ACP_CAPT_LAST1" ),
make_pair( 70512,"EVT_ACP_CAPT_LAST2" ),
make_pair( 70512,"EVT_ACP_CAPT_LAST2" ),
make_pair( 70385, "EVT_ACP_CAPT_MASK_BOOM_SWITCH" ),
make_pair( 70368,"EVT_ACP_CAPT_MIC_FLT" ),
make_pair( 70510,"EVT_ACP_CAPT_MIC_HF1" ),
make_pair( 70511,"EVT_ACP_CAPT_MIC_HF2" )
};
map<int,string> mapTestEvents(TestEvents,TestEvents + sizeof TestEvents / sizeof TestEvents[0]);
int var = 70368;
const char* event = mapTestEvents[var].c_str();
return 0;
}
Please note, I assume the integer value is unique else the whole problem statement would be void.
And yet another way to do it using std::sort and std::lower_bound
#include<iostream>
#include<map>
#include<string>
#include<algorithm>
using namespace std;
struct NameOffset {
string name;
int offset;
};
NameOffset TestEvents[] = {
{ "EVT_ACP_CAPT_LAST1", 70387 },
{ "EVT_ACP_CAPT_LAST1", 70387 },
{ "EVT_ACP_CAPT_LAST2", 70512 },
{ "EVT_ACP_CAPT_LAST2", 70512 },
{ "EVT_ACP_CAPT_MASK_BOOM_SWITCH", 70385 },
{ "EVT_ACP_CAPT_MIC_FLT", 70368 },
{ "EVT_ACP_CAPT_MIC_HF1", 70510 },
{ "EVT_ACP_CAPT_MIC_HF2", 70511 },
};
bool CompareByEvent(NameOffset const& lhs, NameOffset const& rhs) {
return lhs.offset < rhs.offset;
}
int main (){
sort(TestEvents,TestEvents + sizeof TestEvents / sizeof TestEvents[0], &CompareByEvent);
NameOffset var = {"",70510};
const char* event =lower_bound(TestEvents,TestEvents + sizeof TestEvents / sizeof TestEvents[0], var,&CompareByEvent)->name.c_str();
return 0;
}