题目大意：给你两个集合，判断两个集合的关系（不相交、相等、真子集和其他）。简单判断就可以了，不过STL的set没有交集、并集等操作有点让人觉得不方便...
1 #include2 #include 3 #include 4 using namespace std; 5 6 set intersection(const set &a, const set &b) 7 { 8 set ::iterator itA = a.begin(), itB = b.begin(); 9 set c;10 while (itA != a.end() && itB != b.end())11 {12 if (*itA == *itB)13 {14 c.insert(*itA);15 itA++;16 itB++;17 }18 else if (*itA < *itB) itA++;19 else if (*itA > *itB) itB++;20 }21 return c;22 }23 24 int main()25 {26 #ifdef LOCAL27 freopen("in", "r", stdin);28 #endif29 int x;30 while (scanf("%d", &x) != EOF)31 {32 set A, B, C;33 A.insert(x);34 C.insert(x);35 while (getchar() != '\n')36 {37 scanf("%d", &x);38 A.insert(x);39 C.insert(x);40 }41 scanf("%d", &x);42 B.insert(x);43 C.insert(x);44 while (getchar() != '\n')45 {46 scanf("%d", &x);47 B.insert(x);48 C.insert(x);49 }50 if (A.size() + B.size() == C.size()) printf("A and B are disjoint\n"); 51 else if (A == B) printf("A equals B\n");52 else53 {54 set s = intersection(A, B);55 if (A == s) printf("A is a proper subset of B\n");56 else if (B == s) printf("B is a proper subset of A\n");57 else printf("I'm confused!\n");58 }59 }60 return 0;61 }
@2013-11-10 11:50:07
前两天看C++ Primer的时候，看到标准库里有set_union(), set_intersection(), set_difference() 和 set_symmetirc_difference()函数，就重写了一下，提交后和上面那个代码时间一样，不过省了不少功夫哈，对c++还是不熟悉啊，还要多学习。
1 #include2 #include 3 #include 4 #include 5 using namespace std; 6 7 int main() 8 { 9 #ifdef LOCAL10 freopen("in", "r", stdin);11 #endif12 int x;13 while (scanf("%d", &x) != EOF)14 {15 set A, B, C;16 A.insert(x);17 C.insert(x);18 while (getchar() != '\n')19 {20 scanf("%d", &x);21 A.insert(x);22 C.insert(x);23 }24 scanf("%d", &x);25 B.insert(x);26 C.insert(x);27 while (getchar() != '\n')28 {29 scanf("%d", &x);30 B.insert(x);31 C.insert(x);32 }33 if (A.size() + B.size() == C.size()) printf("A and B are disjoint\n");34 else if (A == B) printf("A equals B\n");35 else36 {37 set s;38 set_intersection(A.begin(), A.end(), B.begin(), B.end(), inserter(s, s.begin()));39 if (A == s) printf("A is a proper subset of B\n");40 else if (B == s) printf("B is a proper subset of A\n");41 else printf("I'm confused!\n");42 }43 }44 return 0;45 }