My solutions for USACO train.usaco.org

beads.cpp

/*
ID: sudhaga1
PROG: beads
LANG: C++
*/
#include "iostream"
#include "fstream"
using namespace std;
    	
int main()
{
	ifstream fin ("beads.in");
	ofstream fout ("beads.out");
	int N,index,maxval;
	fin>>N;
	char b[N];
	int sol;
	for (int i = 0; i < N; ++i)
	{
		fin>>b[i];
		//sol[i]=3;
	}
	maxval=0;
	for (int i = 0; i < N; ++i)
	{	
		sol=3;
		//to calculate right beads
		for (int j = i+2; ; ++j)
		{		
			index=i+1;
			if(j>=N){
				j=0;	
			} 
			if(i==N-1){
				index=1;
			}
			if(b[j]==b[index] || b[j]=='w') sol++;
			else break;	
		}
		//to calculate left beads
		for (int j = i-2; ; --j)
		{	
			//normalize i,j
			if(j<0) j=j+N;	
			//if(i<0) i=i+N;
			index=i-1;
			if(i-1<0) index=N-1;
			if(b[j]==b[index] || b[j]=='w') sol++;
			else break;	
		}
		if(sol>maxval){
			maxval=sol;
		}
	}
	fout<<maxval<<endl;
	return 0;
}

calfflac.cpp

/*
ID:sudhaga1
TASK:calfflac
LANG:C++
*/
#include <stdio.h>
#include <string>
#include <fstream>
using namespace std;
#define LET(x,a) __typeof(a) x(a)
#define FOR(i,a,b) for(LET(i,a);i!=(b);++i)
#define REP(i,n) FOR(i,0,n)
//globals
string original,trimmed;
int orginallen,trimlen,longest=0,palinleft,palinright;
int mapOriginToTrim[20001];

void getInput(){
	ifstream fin ("calfflac.in");
	int trimcount=0;
	while(!fin.eof()){
		char a=fin.get();
		original+=a;
	}
	orginallen=	original.length();
	REP(i,orginallen){
		char a=original[i];
		if ((a>=65 && a<=90) || (a>=97 && a<=122)){
			trimmed+=tolower(a);
			mapOriginToTrim[trimcount]=i;
			trimcount++;
		}
	}
	trimlen=trimmed.length();	
}

void findpalin(int l,int r){
	while(l>=0 && r<=trimlen){
		if(trimmed[r]==trimmed[l]){ l--;r++; }
		else break;
	}
	int templongest=r-l-1;
	if(templongest>longest){
		longest=templongest;
		palinleft=mapOriginToTrim[++l];
		palinright=mapOriginToTrim[--r];
	}
}

int main(int argc, char const *argv[])
{
	getInput();
	//REP(i,trimlen) printf("%c", trimmed[i]);   works
	FOR(i,1,trimlen){
		findpalin(i-1,i+1); // for odd length palin
		findpalin(i,i+1);   // for even length palin
	}
	ofstream fout ("calfflac.out");
	fout<<longest<<endl;
	FOR(i,palinleft,palinright+1) fout<<original[i];
	fout<<endl;
	fout.close();	
	return 0;
}

comet.cpp

/*
ID: sudhaga1
PROG: ride
LANG: C++
*/
#include <iostream>
#include <fstream>
#include <string>

using namespace std;

int main() {
	string comet,group;
    ofstream fout ("ride.out");
    ifstream fin ("ride.in");
    fin >> comet >> group;
    int cometsum=1,groupsum=1;
    for (int i = 0; i < comet.size(); ++i)
    {
    	cometsum*=int(comet[i])-64;
    }
    for (int i = 0; i < group.size(); ++i)
    {
    	groupsum*=int(group[i])-64;
    }
    cout<<groupsum<<endl;
        	
    if(cometsum%47==groupsum%47){
    	fout<<"GO"<<endl;
    }
    else	fout<<"STAY"<<endl;

    return 0;
}

crypt1.cpp

/*
ID:sudhaga1
LANG:C++
TASK:crypt1
*/
#include <stdio.h>
#include <fstream>
using namespace std;
#define LET(x,a) __typeof(a) x(a)
#define FOR(i,a,b) for(LET(i,a);i!=(b);++i)
#define REP(i,n) FOR(i,0,n)

//globals
int num[10],numlen;

bool allDigitsValid(int product){
	//printf("All allDigitsValid inside %d\n",product);
	int temp,found;
	while(product){
		found=0;
		temp=product%10;
		REP(i,numlen){
			if(num[i]==temp) found=1;
		}
		if(found==0) return false;
		product=product/10;
	}
	//printf("return true\n");
	return true;
}

int isValid(int n1_hun,int n1_ten,int n1_last,int n2_ten,int n2_last){
	int n1=(100*n1_hun)+(10*n1_ten)+n1_last;
	int n2=(10*n2_ten) +n2_last;
	int product=n1*n2;
	int partial1=n2_last*n1;
	int partial2=n2_ten*n1;
	if(!allDigitsValid(partial1) || partial1>999) {return 0;}
	if(!allDigitsValid(partial2) || partial2>999) {return 0;}
	if(!allDigitsValid(product)  || product>9999 )  {return 0;}
	return 1;
}
int main()
{
	ifstream fin ("crypt1.in");
	ofstream fout ("crypt1.out");
	fin>>numlen;
	int count=0;
	REP(i,numlen) fin>>num[i];
	if(numlen<5) {fout<<count<<endl; return 0;}
	REP(a,numlen){
		REP(b,numlen){
			REP(c,numlen){
				REP(d,numlen){
					REP(e,numlen){
						count+=isValid(num[a],num[b],num[c],num[d],num[e]);
					}
				}
			}
		}
	}
	fout<<count<<endl;
	return 0;
}

dualpal.java

/*
PROB:dualpal
ID:sudhaga1
LANG:JAVA
*/
import java.io.*;
import java.util.*;
public class dualpal {
	public static String toBase(int i,int base){
		char[] digits="0123456789".toCharArray();
		String ret="";
		do{
			ret+=digits[i%base];
			
		}while((i=i/base)>0);
		return new StringBuffer(ret).reverse().toString();
	}
    
	public static void main(String args[]) throws IOException{
		//Scanner sc=new Scanner(System.in);
		BufferedReader br=new BufferedReader(new FileReader("dualpal.in"));
		PrintWriter out=new PrintWriter(new BufferedWriter(new FileWriter("dualpal.out")));
		StringTokenizer st=new StringTokenizer(br.readLine());
		int N=Integer.parseInt(st.nextToken());
		int value=Integer.parseInt(st.nextToken())+1;
		while(N>0){
			int count=0;
			for(int i=2;i<=10;i++){
				String s=toBase(value,i);
				String reverse=new StringBuilder(s).reverse().toString();
				if(s.equals(reverse)){count++; }
				if(count==2) {out.println(value);N--;break;}
			}
			value++;
		}
		br.close();
		out.close();
	}
}

friday13.cpp

/*
ID: sudhaga1
PROG: friday
LANG: C++
*/

#include <iostream>
#include <fstream>
using namespace std;

int mt[]={31,28,31,30,31,30,31,31,30,31,30,31};

int isleap(int y){
	return y%4==0&&(y%100!=0 || y%400==0) ;
}

int mlen(int m,int y){
	if(m==1){
		return mt[m]+ isleap(y);
		}
	else{
		return mt[m];
		}
}
int main()
    	{	
    		int N=20,day;
    		int sol[7]={0,0,0,0,0,0,0};
    		ifstream fin ("friday.in");
    		ofstream fout ("friday.out");
    		fin>>N;
    		day=0;
    		for (int year = 1900; year < 1900+N; ++year)
    		{
				for (int month = 0; month < 12; ++month)
				{
					sol[day]++;
					day=(day+mlen(month,year))	%7;
				}
    		}
    		for (int i = 0; i < 7; ++i)
    		{
    			if(i) fout<<" ";
    			fout<<sol[i];
    		}
    		fout<<endl;
    		return 0;
    	}    	

gift.cpp

/*
ID: sudhaga1
PROG: gift1
LANG: C++
*/
#include "iostream"
#include "fstream"
#include "string"
using namespace std;
struct Friend{
	string name;
	int gi ;
	int re;
};

int main(){
	int j,k,N,money,divide,person;
	string name,receiver;
	ifstream fin ("gift1.in");
	ofstream fout ("gift1.out");
	fin>>N;
	Friend f[N];
	for (int i = 0; i < N; ++i)
	{
		fin>>f[i].name;
		f[i].gi=0;
		f[i].re=0;
	}
	for(int i=0;i<N;i++){
		fin>>name>>money>>divide;
		//cout<<name<<money<<divide;
		person=divide;
		j=0;
		while(f[j].name.compare(name)!=0){
			j++;
		}
		f[j].gi+=money;
		if(divide==0) {f[j].gi+=money;continue;}
		else {
			f[j].gi-=money-((money/divide)*divide);
		}
		//cout<<person<<endl;
		while(person--){
			fin>>receiver;
			k=0;
			while(f[k].name.compare(receiver)!=0){
			k++;
			}
			//cout<<f[k].name<<endl;
			//cout<<money/divide;    	
			f[k].re+=(money/divide);	
		}
	}

	for (int i = 0; i < N; ++i)
	{
		fout<<f[i].name<<" ";
		fout<<f[i].re-f[i].gi<<endl;
		//cout<<f[N].re<<endl;
		  	
	}
	return 0;    	
}

milk.java

/*
ID: sudhaga1
LANG: Java
TASK: milk
*/
import java.io.*;
import java.util.*;
class Pair implements Comparable<Pair>{
	int rate,quan;
	public Pair(int a,int b){
		rate=a;quan=b;
	}
	public int compareTo(Pair p){
		if(this.rate==p.rate){
			if(this.quan<p.quan) return -1;
			else if(this.quan==p.quan) return 0; 
			else return 1;
		}
		else if(this.rate<p.rate) return -1;
		else return 0;
	}
}
public class milk{
	public static void main(String[] args) throws IOException{
		BufferedReader br=new BufferedReader(new FileReader("milk.in"));
		PrintWriter out=new PrintWriter(new BufferedWriter(new FileWriter("milk.out")));
		StringTokenizer st;
		st=new StringTokenizer(br.readLine());
		int total=Integer.parseInt(st.nextToken()),N=Integer.parseInt(st.nextToken()),totalprice=0;
		Pair p[]=new Pair[N];
		for (int i=0; i<N; i++) {
			st=new StringTokenizer(br.readLine());
			p[i]=new Pair(Integer.parseInt(st.nextToken()),Integer.parseInt(st.nextToken()));
		}
		Arrays.sort(p);		        
		for(int i=0;i<N;i++){
			int quantemp=p[i].quan;
			if(quantemp<=total){
				total-=quantemp;
				totalprice+=quantemp*p[i].rate;
			}
			else{
				totalprice+=total*p[i].rate;
				total=0;
			}
		}
		out.println(totalprice+"\n");
	}
}

milk2.cpp

/*
ID: sudhaga1
PROG: milk2
LANG: C++
*/
#include "iostream"
#include <fstream>
#include <vector>
#include <map>
#include <cstdio>
#include <string>
#include <cstring>
using namespace std;

int main()
	{
		ifstream fin ("milk2.in");
		ofstream fout ("milk2.out");
		int N,A=1000000,B=0,maxactive=0,maxidle=0,a,b,cur=0,cur0=0;
		char milk[1000001];
		fin>>N;
		/*
		c[0].start=3;c[0].end=10;
		c[1].start=700;c[1].end=12;
		c[2].start=15;c[2].end=21;		
		*/
		memset(milk,0,sizeof(milk));
		for (int i = 0; i < N; ++i)
		{
			fin>>a>>b;
			A=min(a,A);
			B=max(b,B);
			memset(milk+a,1,b-a);
		}
		
		for (int i = A; i < B; ++i)
		{
			if((int)milk[i]==1){
				cur++;
				if(cur0>maxidle)maxidle=cur0;
				cur0=0;
			}
			else{
				cur0++;
				if(cur>maxactive)maxactive=cur;
				cur=0;
			}
		}
		if(cur0>maxidle)maxidle=cur0;
		if(cur>maxactive)maxactive=cur;
		fout<<maxactive<<" "<<maxidle<<endl;
		//fout<<max<<" "<<maxidle<<endl;
		return 0;
	}	

milkoptimise.cpp

#include <iostream>
#include <string>
#include <stdio.h>
#include <sstream>
#include <algorithm>
#include <queue>
#include <vector>
#include <set>
#include <map>
#include <cmath>
#include <string.h>
#include <fstream>
using namespace std ;
#define sz size()
#define pb push_back
#define _(x,a) memset(x,a,sizeof(x))
#define LET(x,a) __typeof(a) x(a)
#define FOR(i,a,b) for(LET(i,a);i!=(b);++i)
#define REP(i,n) FOR(i,0,n)
#define EACH(i,v) FOR(i,(v).begin(),(v).end())
#define LL long long
#define GI ({int t;scanf("%d",&t);t;})
#define GL ({LL t;scanf("%lld",&t);t;})
#define GD ({double t;scanf("%lf",&t);t;})
#define all(c) c.begin(),c.end()

int main(int argc, char const *argv[])
{
	int quantity=GI,N=GI;
	pair<int,int> v(N);
	REP(i,N){ v[i].first=GI,v[i].second=GI; }
	sort(all(v));
	REP(i,N){cout<<v[i].first<<" "<<v[i].second;} 
	return 0;
}