C++ vector操作--往列表中添加或更新内容

#include <iostream>
#include <string>
#include <vector>
using namespace std;
struct test {
char s;
int score;
};

void print_v1(vector<test> &res) {
vector<test>::iterator it = res.begin();
for (; it != res.end(); ++it) {
cout << "[" << it->s << "," << it->score << "]" << endl;
}
}

void add(vector<test> &res, const test i) {
vector<test>::iterator it2 = res.begin();
bool flag = false;
for (; it2 != res.end(); ++it2) {
if (it2->s == i.s) {
it2->score += i.score;
flag = true;
}
}
if (!flag)
res.push_back(i);
}

int main() {
vector<test> res;
struct test a1;
a1.s = 'A';
a1.score = 20;
struct test a2;
a2.s = 'B';
a2.score = 40;
struct test a3;
a3.s = 'C';
a3.score = 35;
res.push_back(a1);
res.push_back(a2);
res.push_back(a3);

print_v1(res);

struct test i1;
i1.s = 'D';
i1.score = 55;

struct test i2;
i2.s = 'A';
i2.score = 60;

add(res, i1);
add(res, i2);

cout << "------------" << endl;
print_v1(res);

system("pause");
return 0;
}