Codeforces Round #142 (Div. 2)

#include <iostream>
#include <algorithm>
using namespace std;
struct dragon
{
int x;
int y;
}d[1005];
bool cmp(dragon a,dragon b)
{
return a.x<b.x;
}
int main()
{
int s,n,i;
cin>>s>>n;
for(i=0;i<n;i++)
cin>>d[i].x>>d[i].y;
sort(d,d+n,cmp);
for(i=0;i<n;i++)
{
if(s>d[i].x) s+=d[i].y;
else {cout<<"NO"<<endl;return 0;}
}
cout<<"YES"<<endl;
return 0;
}

#include <iostream>
#include <cstdio>
#include <cmath>
#include <cstring>
using namespace std;
int sub[1000002];
int main()
{
long long a,b;
int i,j,n;
memset(sub,0,sizeof(sub));
for(i=2;i<=1e6;i++)
{
if(sub[i]==0)
for(j=i+i;j<=1e6;j+=i)
sub[j]=1;
}
cin>>n;
while(n--)
{
cin>>a;
b=sqrt(a);
if(sub[b]==0&&b*b==a&&a>1) cout<<"YES"<<endl;
else  cout<<"NO"<<endl;
}
return 0;
}

#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
const int MAXN = 105, MAXM = 10005;
const int INF = 999999999;
int N, M, d[MAXN][MAXM];
char mat[MAXN][MAXM];
int main()
{
scanf("%d%d", &N, &M);
for (int i = 1; i <= N; i++)
scanf("%s", mat[i]+1);
fill(d[0]+1, d[0]+1+M, 0);
bool flag = 1;
for (int i = 1; i <= N; i++)
{
flag = 0;
for (int j = 1; j <= M; j++)
{
d[i][j] = INF;
if (mat[i][j] == '1')
flag = 1;
}
if (!flag)
break;
int nst;
for (int j = 1; j <= M; j++)
if (mat[i][j] == '1')
nst = j;
nst -= M;
for (int j = 1; j <= M; j++)
{
if (mat[i][j] == '1')
nst = j;
d[i][j] = min(d[i][j], d[i-1][j]+j-nst);
}
for (int j = M; j >= 1; j--)
if (mat[i][j] == '1')
nst = j;
nst += M;
for (int j = M; j >= 1; j--)
{
if (mat[i][j] == '1')
nst = j;
d[i][j] = min(d[i][j], d[i-1][j]+nst-j);
}
}
int ans = INF;
for (int j = 1; j <= M; j++)
ans = min(ans, d
[j]);
if (flag)
printf("%d\n", ans);
else
printf("-1\n");
return 0;
}