CF AIM Tech Round 3 (Div. 2) D - Recover the String

#include<bits/stdc++.h>
using namespace std;

int main(){
int a,b,c,d;
while(~scanf("%d %d %d %d",&a,&b,&c,&d)) {
int suc = 1;

int t1,t2;
t1 = sqrt(2*a); t2 = sqrt(2*d);
t1 ++; t2 ++;
if(t1*(t1-1) != 2*a || t2*(t2-1) != 2*d) suc = 0;

if(d == 0) {
if(!suc) printf("Impossible\n");
else if(b == 0 && c == 0) {
for(int i = 0; i < t1; ++i) printf("0"); printf("\n");
}else if(b+c == t1) {
if(t1 == 1) {
if(b) printf("01\n");
else printf("10\n");
continue;
}
int cc = 0;
if(cc == b) printf("1");
for(int i = 0; i < t1; ++i) {
printf("0");
cc ++;
if(cc == b) printf("1");
} printf("\n");
}
else printf("Impossible\n");
continue;
}else if(a == 0) {
if(!suc) printf("Impossible\n");
else if(b == 0 && c == 0) {
for(int i = 0; i < t2; ++i) printf("1"); printf("\n");
}else if(b+c == t2) {
int cc = 0;
if(cc == c) printf("0");
for(int i = 0; i < t2; ++i) {
printf("1"); cc ++;
if(cc == c) printf("0");
} printf("\n");
}
else printf("Impossible\n");
continue;
}

if(b+c != t1*t2) suc = 0;
int num1 = 0, pos1 = 0;
num1 = c/t1; pos1 = c%t1;
int all = num1 + (pos1 > 0);
if(all > t2) suc = 0;

if(suc) {
for(int i = 0; i < num1; ++i) printf("1");
int cc = t1;
for(int i = 0; i < t1; ++i) {
cc --;
printf("0");
if(cc == pos1 && cc != 0) printf("1");
}
for(int i = 0; i < t2-all; ++i) printf("1"); printf("\n");
}
else printf("Impossible\n");
}
return 0;
}