习题6-1，UVa673,Time:11.1
#include <iostream>
#include<cstdio>
#include<cstring>
#include<cstdlib>
#include<string>
#include <stack>
using namespace std;
int main() {
int Case;
string str;
bool flag;
scanf("%d",&Case);
for(int c = 1; c <= Case; c++)
{
stack<char>q;
flag = true;
cin>>str;
for(int i = 0; i < str.length(); i++)
{
if(q.size() == 0 || str[i]=='(' || str[i]=='[') q.push(str[i]);
else
{
if((str[i]==')' && q.top()=='(') || (str[i]==']' && q.top()=='['))
{
q.pop();
}
else
{
flag = false;
break;
}
}
}
if(flag==false || q.size()) cout<<"NO"<<endl;
else cout<<"YES"<<endl;
}
return 0;
}
习题6-2，UVa712,Time:11.1
#include <iostream>
#include <cstdio>
#include <string>
#include <cstring>
using namespace std;
struct node
{
int l, r, s;
}num[1<<8+10];
int n, m;
int ans[1005];
string str;
int build(int i, int l, int r)
{
num[i].l = l;
num[i].r = r;
if(l == r)
{
num[i].s = str[l-1] - '0';
}
else
{
build(i+i, l, (l+r)>>1);
build(i+i+1,((l+r)>>1)+1,r);
}
}
int solve()
{
int k = 1;
for(int i = 0; i < n; i++)
{
k+=k;
k+=(str[i] - '0');
}
return num[k].s;
}
int main()
{
while( cin>>n )
{
cin>>str;
build(1, 1, 1<<n);
cin>>m;
for(int i = 0; i < m; i++)
{
cin>>str;
ans[i] = solve();
}
for(int i = 0; i < m; i++)
cout<<ans[i];
cout<<endl;
}
return 0;
}
习题6-3，UVa536,Time:11.2
#include <iostream>
#include <cstdio>
#include <string>
#include <cstring>
using namespace std;
char pre_order[100005];
char in_order[100005];
char post_order[100005];
int pl, il;
int dfs(char* spo, char* fpo, char* sio, char* fio)
{
if(fpo < spo || fio < sio) return 0;
char g = *spo;
int sn = 0;
while(*(sio + sn) != g) sn++;
dfs(spo + 1, spo + sn, sio, sio + sn);
dfs(spo + sn + 1, fpo, sio + sn + 1, fio);
cout<<*spo;
}
int main()
{
freopen("in.txt","r",stdin);
while( cin>>pre_order>>in_order )
{
pl = strlen(pre_order);
il = strlen(in_order);
dfs(pre_order, pre_order + pl - 1, in_order, in_order + il - 1);
cout<<endl;
}
return 0;
}
习题6-4，UVa439,Time:11.2
#include <iostream>
#include <cstdio>
#include <string>
#include <cstring>
#include <queue>
using namespace std;
int d[10][2] = {{1,2},{2,1},{-1,2},{2,-1},{-2,1},{1,-2},{-1,-2},{-2,-1}};
int map[10][10];
struct node
{
bool operator <(const node &a)const
{
return a.s<s;
}
int x, y, s;
};
int main()
{
int x, y;
int ex, ey;
node v, u;
freopen("in.txt","r",stdin);
while(cin>>x>>y)
{
memset(map,0,sizeof(map));
cin>>ex>>ey;
priority_queue<node>q;
v.x = x;
v.y = y;
v.s = 0;
q.push(v);
while(1)
{
v = q.top();
q.pop();
if(map[v.x][v.y] == 0)
map[v.x][v.y] = v.s;
else
continue;
if(v.x == ex && v.y == ey)
{
cout<<v.s;
break;
}
for(int i = 0; i < 8; i++)
{
u.x = v.x + d[i][0];
u.y = v.y + d[i][1];
u.s = v.s + 1;
if(u.x > 0 && u.y <= 8 && u.x <=8 && u.y >0 && map[u.x][u.y] == 0)
q.push(u);
}
}
}
return 0;
}
习题6-5，UVa1600,Time:11.2
#include <iostream>
#include <cstdio>
#include <string>
#include <cstring>
#include <queue>
using namespace std;
int map[25][25];
int stp[25][25];
int d[5][2]={{1,0},{0,1},{-1,0},{0,-1}};
struct node
{
bool operator <(const node &a )const
{
return a.s<s;
}
int x, y, s, k;
};
int main()
{
freopen("in.txt","r",stdin);
int m, n, x;
node v, u;
while(cin>>m>>n)
{
memset(map,0,sizeof(map));
memset(stp,0,sizeof(stp));
priority_queue<node>q;
for(int i = 1; i <= m; i++)
for(int j = 1; j <= n; j++)
cin>>map[i][j];
v.x = 1;
v.y = 1;
v.s = 1;
stp[v.x][v.y] = v.s;
q.push(v);
while(1)
{
v = q.top();
q.pop();
if(v.x == m && v.y == n)
{
cout<<v.s-1<<endl;
break;
}
stp[v.x][v.y] = v.s;
for(int i = 0; i < 4; i++)
{
u.x = v.x + d[i][0];
u.y = v.y + d[i][1];
u.s = v.s + 1;
if(u.x > 0 && u.x <=m && u.y > 0 && u.y <= n && stp[u.x][u.y]==0 && v.k*map[u.x][u.y]==0)
{
u.k = map[u.x][u.y];
q.push(u);
}
}
}
}
return 0;
}
习题6-6，UVa1600,Time:11.2
/*
5
1 2
1 3
2 4
2 5
0 0 6 3 7
*/
#include <iostream>
#include <stdio.h>
#include <string>
#include <cstring>
#include <map>
#include <queue>
using namespace std;
vector<int>tree[2005];
int num[2005];
int cur[2005];
void sec_dfs(int n, int f)
{
for(int i = 0; i < tree[n].size(); i++)
{
if(tree[n][i] != f)
{
cur[tree[n][i]] = cur[n] >> 1;
sec_dfs(tree[n][i],n);
}
}
}
int fir_dfs(int n, int f)
{
int s = 0;
int m = 0;
for(int i = 0; i < tree[n].size(); i++)
{
if(tree[n][i] != f)
{
m = fir_dfs(tree[n][i], n);
s = max(m, s);
}
}
if(s == 0) return 1;
return 2*s;
}
int ans(int n)
{
int maxx = 0;
int s = 0;
map<double,int>mul;
for(int i = 1; i <= n; i++)
if(num[i])
{
s++;
mul[(num[i]*1.0 / cur[i]*1.0)]++;
if(mul[(num[i]*1.0 / cur[i]*1.0)] > maxx) maxx = mul[(num[i]*1.0 / cur[i]*1.0)];
}
return s-maxx;
}
int main()
{
freopen("in.txt","r",stdin);
int n, m;
int s, t;
while(cin>>n)
{
m = 0;
for(int i = 1; i < n; i++)
{
cin>>s>>t;
tree[s].push_back(t);
tree[t].push_back(s);
}
for(int i = 1; i <= n; i++)
{
cin>>num[i];
m = num[i]>m?num[i]:m;
}
cur[1] = fir_dfs(1,0);
sec_dfs(1,0);
// for(int i = 1; i <= n; i++)
// cout<<cur[i]<<" ";
cout<<ans(n)<<endl;
}
return 0;
}
习题6-8，UVa806,Time:11.4
#include <iostream>
#include <vector>
#include <cmath>
#include <queue>
using namespace std;
struct node
{
int xl, xr, yl, yr;
int s, t;
int sum;
}num[1000005];
priority_queue<int>ans;
void build(int xl, int xr, int yl, int yr, int i, int cur)
{
num[i].xl = xl;
num[i].yl = yl;
num[i].xr = xr;
num[i].yr = yr;
num[i].sum = (xr - xl + 1) * (yr - yl + 1);
num[i].s = 0;
num[i].t = cur;
if(xl == xr && yl == yr) return;
int mx = (xl + xr)>>1;
int my = (yl + yr)>>1;
build(xl, mx, yl, my, 4*i - 2, 1);
build(mx + 1, xr, yl, my, 4*i - 1, 2);
build(xl, mx, my + 1, yr, 4*i, 3);
build(mx + 1, xr, my + 1, yr, 4*i + 1, 4);
}
void update(int x, int y, int i)
{
if(num[i].xl == num[i].xr && num[i].yl == num[i].yr)
{
num[i].s = 1;
return;
}
int mx = (num[i].xl + num[i].xr)>>1;
int my = (num[i].yl + num[i].yr)>>1;
if(x <= mx && y <= my)
{
update(x, y, i*4 - 2);
}
else if(x > mx && y <= my)
{
update(x, y, i*4 - 1);
}
else if(x <= mx && y > my)
{
update(x, y, i*4);
}
else
{
update(x, y, i*4 + 1);
}
num[i].s++;
}
void dfs(int i, int way, int n)
{
if(num[i].s == 0) return;
else if(num[i].s == num[i].sum)
{
ans.push(-way);
return;
}
else
{
dfs(i*4 - 2, way + 1*pow(10, n), n + 1);
dfs(i*4 - 1, way + 3*pow(10, n), n + 1);
dfs(i*4, way + 2*pow(10, n), n + 1);
dfs(i*4 + 1, way + 4*pow(10, n), n + 1);
}
}
int FtoT(int x)
{
x *= -1;
int s = 0;
int d = 0;
int k;
while(x)
{
k = x % 10;
s += k*pow(5, d++);
x/=10;
}
return s;
}
int main()
{
freopen("in.txt","r",stdin);
int n, m;
cin>>n;
build(1, n, 1, n, 1, 0);
for(int i = 1; i <= n; i++)
{
for(int j = 1; j <= n; j++)
{
cin>>m;
if(m) update(i, j, 1);
}
}
dfs(1, 0, 0);
while(ans.size())
{
cout<<FtoT(ans.top())<<" ";
ans.pop();
}
return 0;
}
习题6-9，UVa127,Time:11.5
#include <iostream>
#include <cstdio>
#include <cstring>
#include <vector>
#include <queue>
#include <stack>
using namespace std;
struct node
{
char n, f;
};
vector<stack<node> >pokelist;
bool init()
{
bool flag = false;
node v, v1, v3;
for(int i = 0; i < pokelist.size(); i++)
{
int xflag = false;
if(pokelist[i].size() == 0) continue;
v = pokelist[i].top();
if(i >= 3)
{
v3 = pokelist[i-3].top();
if(v.n == v3.n || v.f == v3.f)
{
xflag = true;
pokelist[i].pop();
pokelist[i-3].push(v);
flag = true;
}
}
if(i >= 1 && xflag == false)
{
v1 = pokelist[i-1].top();
if(v.n == v1.n || v.f == v1.f)
{
pokelist[i].pop();
pokelist[i-1].push(v);
flag = true;
}
}
if(pokelist[i].size() == 0)
{
pokelist.erase(pokelist.begin()+i);
i--;
}
if(flag) return flag;
}
return flag;
}
int main()
{
freopen("in.txt","r",stdin);
char poke[5];
node v;
int size;
for(int i = 1; i <= 52; i++)
{
stack<node>q;
cin>>poke;
cout<<poke<<" : ";
v.f = poke[1];
v.n = poke[0];
q.push(v);
pokelist.push_back(q);
while(init());
}
for(int i = 0; i < pokelist.size(); i++)
cout<<pokelist[i].size()<<" ";
cout<<endl;
return 0;
}
习题6-11，UVa10410,Time:11.4
#include <iostream>
#include <cstdio>
#include <cstring>
#include <vector>
using namespace std;
char cdfs[1005];
char cbfs[1005];
vector<int>dot[1005];
void dfs(char ds[], char bs[], int len)
{
if(len == 1) return;
int cur[1005];
char dtmp[1005];
char btmp[1005];
int k, xl = 0;
int a, b;
for(int i = 0; i < len; i++)
{
cur[ds[i]-'0'] = i;
}
for(int i = 1; i < len; i++)
{
k = 0;
if(cur[bs[i] - '0'] > cur[bs[i+1] - '0'])
{
xl = i;
break;
}
a = bs[0] - '0';
b = bs[i] - '0';
dot[a].push_back(b);
for(int j = i; j < len; j++)
{
if(cur[bs[j] - '0'] >= cur[bs[i] - '0'] && cur[bs[j] - '0'] < cur[bs[i + 1] - '0'])
btmp[k++] = bs[j];
}
btmp[k++] = 0;
k = 0;
for(int j = cur[bs[i] - '0']; j < cur[bs[i+1] - '0']; j++)
dtmp[k++] = ds[j];
dtmp[k++] = 0;
dfs(dtmp, btmp, k - 1);
}
a = bs[0] - '0';
b = bs[xl] - '0';
dot[a].push_back(b);
k = 0;
for(int j = xl; j < len; j++)
if(cur[bs[j] - '0'] >= cur[bs[xl] - '0'])
btmp[k++] = bs[j];
btmp[k++] = 0;
k = 0;
for(int j = cur[bs[xl] - '0']; j < len; j++)
dtmp[k++] = ds[j];
dtmp[k++] = 0;
dfs(dtmp, btmp, k - 1);
}
int main()
{
freopen("in.txt","r",stdin);
int n;
cin>>n;
cin>>cdfs>>cbfs;
dfs(cdfs, cbfs, n);
for(int i = 1; i <= n; i++)
{
cout<<i<<" : ";
for(int j = 0; j < dot[i].size(); j++)
{
cout<<dot[i][j]<<" ";
}
cout<<endl;
}
return 0;
}
习题6-14，UVa12118,Time:11.5
#include <iostream>
#include <cstdio>
#include <cstring>
#include <vector>
#include <queue>
#include <stack>
using namespace std;
int main()
{
freopen("in.txt","r",stdin);
int map[1005];
int v, e, t;
while(cin>>v>>e>>t)
{
int x, y, z = 0;
memset(map,0,sizeof(map));
for(int i = 0; i < e; i++)
{
cin>>x>>y;
map[x]++;
map[y]++;
}
for(int i = 1; i <= v; i++)
if(map[i]%2) z++;
cout<<z/2 + e - 1<<endl;
}
return 0;
}