[CCF2015.09]题解(待填

Posted 2020-07-04

201509-1 数列分段

水，记下前一个数，看看跟当前是否一样，不一样就ans+1

 1 #include <algorithm>
 2 #include <iostream>
 3 #include <iomanip>
 4 #include <cstring>
 5 #include <climits>
 6 #include <complex>
 7 #include <fstream>
 8 #include <cassert>
 9 #include <cstdio>
10 #include <bitset>
11 #include <vector>
12 #include <deque>
13 #include <queue>
14 #include <stack>
15 #include <ctime>
16 #include <set>
17 #include <map>
18 #include <cmath>
19 
20 using namespace std;
21 
22 int n, a;
23 
24 int main() {
25     // freopen("in", "r", stdin);
26     while(~scanf("%d", &n)) {
27         scanf("%d", &a);
28         int cur = a, cnt = 1;
29         for(int i = 1; i < n; i++) {
30             scanf("%d", &a);
31             if(cur != a) {
32                 cnt++;
33                 cur = a;
34             }
35         }
36         printf("%d\\n", cnt);
37     }
38     return 0;
39 }

1

 

201509-2 日期计算

打表，注意细节就行

 1 #include <algorithm>
 2 #include <iostream>
 3 #include <iomanip>
 4 #include <cstring>
 5 #include <climits>
 6 #include <complex>
 7 #include <fstream>
 8 #include <cassert>
 9 #include <cstdio>
10 #include <bitset>
11 #include <vector>
12 #include <deque>
13 #include <queue>
14 #include <stack>
15 #include <ctime>
16 #include <set>
17 #include <map>
18 #include <cmath>
19 
20 using namespace std;
21 
22 const int com[15] = {0,31,59,90,120,151,181,212,243,273,304,334, 365};
23 const int lep[15] = {0,31,60,91,121,152,182,213,244,274,305,335, 366};
24 int y, c, m, d;
25 
26 int main() {
27     // freopen("in", "r", stdin);
28     while(~scanf("%d %d", &y, &c)) {
29         d = 0;
30         if((y % 4 == 0 && y % 100 != 0) || (y % 400 == 0)) {
31             for(int i = 1; i <= 12; i++) {
32                 if(lep[i] < c) {
33                     m = i;
34                 }
35                 else break;
36             }
37             d = c - lep[m];
38             m++;
39             if(d != 0) printf("%d\\n%d\\n", m, d);
40             else printf("%d\\n%d\\n", m, lep[m]-lep[m-1]);
41         }
42         else {
43             for(int i = 1; i <= 12; i++) {
44                 if(com[i] < c) {
45                     m = i;
46                 }
47                 else break;
48             }
49             d = c - com[m];
50             m++;
51             if(d != 0) printf("%d\\n%d\\n", m, d);
52             else printf("%d\\n%d\\n", m, com[m]-com[m-1]);
53         }
54     }
55     return 0;
56 }

2

 

201509-4 高速公路

求多少个连通对。先tarjan跑出所有连通分量，然后枚举任意两个不相等的点，看看是否属于同一个连通分量里。

  1 #include <algorithm>
  2 #include <iostream>
  3 #include <iomanip>
  4 #include <cstring>
  5 #include <climits>
  6 #include <complex>
  7 #include <fstream>
  8 #include <cassert>
  9 #include <cstdio>
 10 #include <bitset>
 11 #include <vector>
 12 #include <deque>
 13 #include <queue>
 14 #include <stack>
 15 #include <ctime>
 16 #include <set>
 17 #include <map>
 18 #include <cmath>
 19 
 20 using namespace std;
 21 
 22 const int maxn = 10010;
 23 const int maxm = 100010;
 24 typedef struct Edge {
 25     int u;
 26     int v;
 27     int next;
 28     Edge() { next = -1; }
 29 }Edge;
 30 
 31 int head[maxn], ecnt;
 32 Edge edge[maxm];
 33 int n, m;
 34 
 35 int bcnt, dindex;
 36 int dfn[maxn], low[maxn];
 37 int stk[maxn], top;
 38 int belong[maxn];
 39 bool instk[maxn];
 40 
 41 void init() {
 42     memset(edge, 0, sizeof(edge));
 43     memset(head, -1, sizeof(head));
 44     memset(instk, 0, sizeof(instk));
 45     memset(dfn, 0, sizeof(dfn));
 46     memset(low, 0, sizeof(low));
 47     memset(belong, 0, sizeof(belong));
 48     ecnt = top = bcnt = dindex = 0;
 49 }
 50 
 51 void adde(int uu, int vv) {
 52     edge[ecnt].u = uu;
 53     edge[ecnt].v = vv;
 54     edge[ecnt].next = head[uu];
 55     head[uu] = ecnt++;
 56 }
 57 
 58 void tarjan(int u) {
 59     int v = u;
 60     dfn[u] = low[u] = ++dindex;
 61     stk[++top] = u;
 62     instk[u] = 1;
 63     for(int i = head[u]; ~i; i=edge[i].next) {
 64         v = edge[i].v;
 65         if(!dfn[v]) {
 66             tarjan(v);
 67             low[u] = min(low[u], low[v]);
 68         }
 69         else if(instk[v] && dfn[v] < low[u]) {
 70             low[u] = dfn[v];
 71         }
 72     }
 73     if(dfn[u] == low[u]) {
 74         bcnt++;
 75         do {
 76             v = stk[top--];
 77             instk[v] = 0;
 78             belong[v] = bcnt;
 79         } while(v != u);
 80     }
 81 }
 82 
 83 int main() {
 84     // freopen("in", "r", stdin);
 85     int uu, vv;
 86     while(~scanf("%d %d", &n, &m)) {
 87         init();
 88         for(int i = 0; i < m; i++) {
 89             scanf("%d %d", &uu, &vv);
 90             adde(uu, vv);
 91         }
 92         for(uu = 1; uu <= n; uu++) {
 93             if(!dfn[uu]) {
 94                 tarjan(uu);
 95             }
 96         }
 97         int ans = 0;
 98         for(int i = 1; i <= n; i++) {
 99             for(int j = i + 1; j <= n; j++) {
100                 if(belong[i] == belong[j]) {
101                     ans++;
102                 }
103             }
104         }
105         printf("%d\\n", ans);
106     }
107     return 0;
108 }

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