BZOJ1108（思路）

题目本质：因为只能往南和往东走所以不管怎么组合方案结果都是一样的Orz……我太菜了想不到嘤嘤嘤

 1 #pragma comment(linker, "/STACK:1024000000,1024000000")
 2 #include <cstdio>
 3 #include <cstring>
 4 #include <cstdlib>
 5 #include <cmath>
 6 #include <ctime>
 7 #include <cctype>
 8 #include <climits>
 9 #include <iostream>
10 #include <iomanip>
11 #include <algorithm>
12 #include <string>
13 #include <sstream>
14 #include <stack>
15 #include <queue>
16 #include <set>
17 #include <map>
18 #include <vector>
19 #include <list>
20 #include <fstream>
21 #include <bitset>
22 #define init(a, b) memset(a, b, sizeof(a))
23 #define rep(i, a, b) for (int i = a; i <= b; i++)
24 #define irep(i, a, b) for (int i = a; i >= b; i--)
25 using namespace std;
26 
27 typedef double db;
28 typedef long long ll;
29 typedef unsigned long long ull;
30 typedef pair<int, int> P;
31 const int inf = 0x3f3f3f3f;
32 const ll INF = 1e18;
33 
34 template <typename T> void read(T &x) {
35     x = 0;
36     int s = 1, c = getchar();
37     for (; !isdigit(c); c = getchar())
38         if (c == '-')    s = -1;
39     for (; isdigit(c); c = getchar())
40         x = x * 10 + c - 48;
41     x *= s;
42 }
43 
44 template <typename T> void write(T x) {
45     if (x < 0)    x = -x, putchar('-');
46     if (x > 9)    write(x / 10);
47     putchar(x % 10 + '0');
48 }
49 
50 template <typename T> void writeln(T x) {
51     write(x);
52     puts("");
53 }
54 
55 const int maxn = 5e4 + 5;
56 int n, x, y;
57 ll ans;
58 
59 int main() {
60     read(n);
61     rep(i, 1, n) {
62         read(x), read(y);
63         ans += y - x;
64     }
65     rep(i, 1, n) {
66         read(x), read(y);
67         ans += x - y;
68     }
69     writeln(ans);
70     return 0;
71 }